Matthew Wilcox (Oracle) [Fri, 26 Apr 2024 14:45:01 +0000 (15:45 +0100)]
mm: delay the check for a NULL anon_vma
Instead of checking the anon_vma early in the fault path where all page
faults pay the cost, delay it until we know we're going to need the
anon_vma to be filled in. This will have a slight negative effect on the
first fault in an anonymous VMA, but it shortens every other page fault.
It also makes the code slightly cleaner as the anon and file backed fault
handling look more similar.
The Intel kernel test bot reports a 3x improvement in vm-scalability
throughput with the small-allocs-mt test. This is clearly an extreme
situation that won't be replicated in any real-world workload, but it's a
nice win.
https://lore.kernel.org/all/
202404261055.
c5e24608-oliver.sang@intel.com/
Link: https://lkml.kernel.org/r/20240426144506.1290619-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 26 Apr 2024 14:45:00 +0000 (15:45 +0100)]
mm: assert the mmap_lock is held in __anon_vma_prepare()
Patch series "Improve anon_vma scalability for anon VMAs".
We have a 3x throughput improvement reported by Intel's kernel test robot:
https://lore.kernel.org/all/
202404261055.
c5e24608-oliver.sang@intel.com/
This is from delaying taking the mmap_lock for page faults until we
actually need the mmap_lock in order to assign an anon_vma to the vma. It
cleans up the page fault path a little by making the anon fault handler
more similar to the file fault handler.
This patch (of 4):
Convert the comment into an assertion.
Link: https://lkml.kernel.org/r/20240426144506.1290619-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240426144506.1290619-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox [Thu, 25 Apr 2024 04:00:55 +0000 (05:00 +0100)]
mm: simplify thp_vma_allowable_order
Combine the three boolean arguments into one flags argument for
readability.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Thu, 25 Apr 2024 13:17:24 +0000 (21:17 +0800)]
mm: remove stale comment __folio_mark_dirty
The __folio_mark_dirty will not mark inode dirty any longer. Remove the
stale comment of it.
Link: https://lkml.kernel.org/r/20240425131724.36778-5-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Howard Cochran <hcochran@kernelspring.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Thu, 25 Apr 2024 13:17:23 +0000 (21:17 +0800)]
mm: call __wb_calc_thresh instead of wb_calc_thresh in wb_over_bg_thresh
Call __wb_calc_thresh to calculate wb bg_thresh of gdtc in
wb_over_bg_thresh to remove unnecessary wrap in wb_calc_thresh.
Link: https://lkml.kernel.org/r/20240425131724.36778-4-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Howard Cochran <hcochran@kernelspring.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Thu, 25 Apr 2024 13:17:22 +0000 (21:17 +0800)]
mm: correct calculation of wb's bg_thresh in cgroup domain
wb_calc_thresh() is calculating wb's share of bg_thresh in the global
domain. However in case of cgroup writeback this is not the right
thing to do. Consider the following domain hierarchy:
global domain (> 20G)
/ \
cgroup1 (10G) cgroup2 (10G)
| |
bdi wb1 wb2
and assume wb1 and wb2 have the same bandwidth and the background
threshold is set at 10%. The bg_thresh of cgroup1 and cgroup2 is going
to be 1G. Now because wb_calc_thresh(mdtc->wb, mdtc->bg_thresh)
calculates per-wb threshold in the global domain as (wb bandwidth) /
(domain bandwidth) it returns bg_thresh for wb1 as 0.5G although it has
nobody to compete against in cgroup1.
Fix the problem by calculating wb's share of bg_thresh in the cgroup
domain.
Test as following:
/* make it easier to observe the issue */
echo 300000 > /proc/sys/vm/dirty_expire_centisecs
echo 100 > /proc/sys/vm/dirty_writeback_centisecs
/* run fio in wb1 */
cd /sys/fs/cgroup
echo "+memory +io" > cgroup.subtree_control
mkdir group1
cd group1
echo 10G > memory.high
echo 10G > memory.max
echo $$ > cgroup.procs
mkfs.ext4 -F /dev/vdb
mount /dev/vdb /bdi1/
fio -name test -filename=/bdi1/file -size=600M -ioengine=libaio -bs=4K \
-iodepth=1 -rw=write -direct=0 --time_based -runtime=600 -invalidate=0
/* run fio in wb2 with a new shell */
cd /sys/fs/cgroup
mkdir group2
cd group2
echo 10G > memory.high
echo 10G > memory.max
echo $$ > cgroup.procs
mkfs.ext4 -F /dev/vdc
mount /dev/vdc /bdi2/
fio -name test -filename=/bdi2/file -size=600M -ioengine=libaio -bs=4K \
-iodepth=1 -rw=write -direct=0 --time_based -runtime=600 -invalidate=0
Before fix, the wrttien pages of wb1 and wb2 reported from
toos/writeback/wb_monitor.py keep growing. After fix, rare written pages
are accumulated.
There is no obvious change in fio result.
[jack@suse.cz: changelog rewording]
Link: https://lkml.kernel.org/r/20240425131724.36778-3-shikemeng@huaweicloud.com
Fixes: 74d369443325 ("writeback: Fix performance regression in wb_over_bg_thresh()")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Howard Cochran <hcochran@kernelspring.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Thu, 25 Apr 2024 13:17:21 +0000 (21:17 +0800)]
mm: enable __wb_calc_thresh to calculate dirty background threshold
Patch series "Fix and cleanups to page-writeback", v2.
This series contains some random cleanups and a fix to correct calculation
of wb's bg_thresh in cgroup domain. More details can be found respective
patches.
This patch (of 4):
Originally, __wb_calc_thresh always calculate wb's share of dirty
throttling threshold. By getting thresh of wb_domain from caller,
__wb_calc_thresh could be used for both dirty throttling and dirty
background threshold.
This is a preparation to correct threshold calculation of wb in cgroup.
Link: https://lkml.kernel.org/r/20240425131724.36778-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20240425131724.36778-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Howard Cochran <hcochran@kernelspring.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Tue, 23 Apr 2024 03:46:43 +0000 (11:46 +0800)]
writeback: rename nr_reclaimable to nr_dirty in balance_dirty_pages
Commit
8d92890bd6b85 ("mm/writeback: discard NR_UNSTABLE_NFS, use
NR_WRITEBACK instead") removed NR_UNSTABLE_NFS and nr_reclaimable only
contains dirty page now. Rename nr_reclaimable to nr_dirty properly.
Link: https://lkml.kernel.org/r/20240423034643.141219-6-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Tue, 23 Apr 2024 03:46:42 +0000 (11:46 +0800)]
writeback: add wb_monitor.py script to monitor writeback info on bdi
Add wb_monitor.py script to monitor writeback information on backing dev
which makes it easier and more convenient to observe writeback behaviors
of running system.
The wb_monitor.py script is written based on wq_monitor.py.
Following domain hierarchy is tested:
global domain (320G)
/ \
cgroup domain1(10G) cgroup domain2(10G)
| |
bdi wb1 wb2
The wb_monitor.py script output is as following:
./wb_monitor.py 252:16 -c
writeback reclaimable dirtied written avg_bw
252:16_1 0 0 0 0 102400
252:16_4284 672 820064
9230368 8410304 685612
252:16_4325 896 819840
10491264 9671648 652348
252:16 1568
1639904 19721632 18081952 1440360
writeback reclaimable dirtied written avg_bw
252:16_1 0 0 0 0 102400
252:16_4284 672 820064
9230368 8410304 685612
252:16_4325 896 819840
10491264 9671648 652348
252:16 1568
1639904 19721632 18081952 1440360
...
Link: https://lkml.kernel.org/r/20240423034643.141219-5-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Tue, 23 Apr 2024 03:46:40 +0000 (11:46 +0800)]
writeback: support retrieving per group debug writeback stats of bdi
Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats
of bdi.
Following domain hierarchy is tested:
global domain (320G)
/ \
cgroup domain1(10G) cgroup domain2(10G)
| |
bdi wb1 wb2
/* per wb writeback info of bdi is collected */
cat wb_stats
WbCgIno: 1
WbWriteback: 0 kB
WbReclaimable: 0 kB
WbDirtyThresh: 0 kB
WbDirtied: 0 kB
WbWritten: 0 kB
WbWriteBandwidth: 102400 kBps
b_dirty: 0
b_io: 0
b_more_io: 0
b_dirty_time: 0
state: 1
WbCgIno: 4091
WbWriteback: 1792 kB
WbReclaimable: 820512 kB
WbDirtyThresh:
6004692 kB
WbDirtied:
1820448 kB
WbWritten: 999488 kB
WbWriteBandwidth: 169020 kBps
b_dirty: 0
b_io: 0
b_more_io: 1
b_dirty_time: 0
state: 5
WbCgIno: 4131
WbWriteback: 1120 kB
WbReclaimable: 820064 kB
WbDirtyThresh:
6004728 kB
WbDirtied:
1822688 kB
WbWritten:
1002400 kB
WbWriteBandwidth: 153520 kBps
b_dirty: 0
b_io: 0
b_more_io: 1
b_dirty_time: 0
state: 5
[shikemeng@huaweicloud.com: fix build problems]
Link: https://lkml.kernel.org/r/20240423034643.141219-4-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20240423034643.141219-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kemeng Shi [Tue, 23 Apr 2024 03:46:39 +0000 (11:46 +0800)]
writeback: collect stats of all wb of bdi in bdi_debug_stats_show
Patch series "Improve visibility of writeback", v5.
This series tries to improve visilibity of writeback. Patch 1 make
/sys/kernel/debug/bdi/xxx/stats show writeback info of whole bdi instead
of only writeback info in root cgroup. Patch 2 add a new debug file
/sys/kernel/debug/bdi/xxx/wb_stats to show per wb writeback info. Patch 3
add wb_monitor.py to monitor basic writeback info of running system, more
info could be added on demand. Patch 4 is a random cleanup. More details
can be found in respective patches.
Following domain hierarchy is tested:
global domain (320G)
/ \
cgroup domain1(10G) cgroup domain2(10G)
| |
bdi wb1 wb2
/* all writeback info of bdi is successfully collected */
cat stats
BdiWriteback: 4704 kB
BdiReclaimable:
1294496 kB
BdiDirtyThresh:
204208088 kB
DirtyThresh:
195259944 kB
BackgroundThresh:
32503588 kB
BdiDirtied:
48519296 kB
BdiWritten:
47225696 kB
BdiWriteBandwidth:
1173892 kBps
b_dirty: 1
b_io: 0
b_more_io: 1
b_dirty_time: 0
bdi_list: 1
state: 1
/* per wb writeback info of bdi is collected */
cat /sys/kernel/debug/bdi/252:16/wb_stats
WbCgIno: 1
WbWriteback: 0 kB
WbReclaimable: 0 kB
WbDirtyThresh: 0 kB
WbDirtied: 0 kB
WbWritten: 0 kB
WbWriteBandwidth: 102400 kBps
b_dirty: 0
b_io: 0
b_more_io: 0
b_dirty_time: 0
state: 1
WbCgIno: 4208
WbWriteback: 59808 kB
WbReclaimable: 676480 kB
WbDirtyThresh:
6004624 kB
WbDirtied:
23348192 kB
WbWritten:
22614592 kB
WbWriteBandwidth: 593204 kBps
b_dirty: 1
b_io: 1
b_more_io: 0
b_dirty_time: 0
state: 7
WbCgIno: 4249
WbWriteback: 144256 kB
WbReclaimable: 432096 kB
WbDirtyThresh:
6004344 kB
WbDirtied:
25727744 kB
WbWritten:
25154752 kB
WbWriteBandwidth: 577904 kBps
b_dirty: 0
b_io: 1
b_more_io: 0
b_dirty_time: 0
state: 7
The wb_monitor.py script output is as following:
./wb_monitor.py 252:16 -c
writeback reclaimable dirtied written avg_bw
252:16_1 0 0 0 0 102400
252:16_4284 672 820064
9230368 8410304 685612
252:16_4325 896 819840
10491264 9671648 652348
252:16 1568
1639904 19721632 18081952 1440360
writeback reclaimable dirtied written avg_bw
252:16_1 0 0 0 0 102400
252:16_4284 672 820064
9230368 8410304 685612
252:16_4325 896 819840
10491264 9671648 652348
252:16 1568
1639904 19721632 18081952 1440360
...
This patch (of 5):
/sys/kernel/debug/bdi/xxx/stats is supposed to show writeback information
of whole bdi, but only writeback information of bdi in root cgroup is
collected. So writeback information in non-root cgroup are missing now.
To be more specific, considering following case:
/* create writeback cgroup */
cd /sys/fs/cgroup
echo "+memory +io" > cgroup.subtree_control
mkdir group1
cd group1
echo $$ > cgroup.procs
/* do writeback in cgroup */
fio -name test -filename=/dev/vdb ...
/* get writeback info of bdi */
cat /sys/kernel/debug/bdi/xxx/stats
The cat result unexpectedly implies that there is no writeback on target
bdi.
Fix this by collecting stats of all wb in bdi instead of only wb in
root cgroup.
Following domain hierarchy is tested:
global domain (320G)
/ \
cgroup domain1(10G) cgroup domain2(10G)
| |
bdi wb1 wb2
/* all writeback info of bdi is successfully collected */
cat stats
BdiWriteback: 2912 kB
BdiReclaimable:
1598464 kB
BdiDirtyThresh:
167479028 kB
DirtyThresh:
195038532 kB
BackgroundThresh:
32466728 kB
BdiDirtied:
19141696 kB
BdiWritten:
17543456 kB
BdiWriteBandwidth:
1136172 kBps
b_dirty: 2
b_io: 0
b_more_io: 1
b_dirty_time: 0
bdi_list: 1
state: 1
Link: https://lkml.kernel.org/r/20240423034643.141219-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20240423034643.141219-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ryan Roberts [Wed, 24 Apr 2024 10:53:01 +0000 (11:53 +0100)]
selftests/mm: soft-dirty should fail if a testcase fails
Previously soft-dirty was unconditionally exiting with success, even if
one of its testcases failed. Let's fix that so that failure can be
reported to automated systems properly.
Link: https://lkml.kernel.org/r/20240424105301.3157695-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hariom Panthi [Wed, 24 Apr 2024 11:18:38 +0000 (16:48 +0530)]
mm: vmalloc: dump page owner info if page is already mapped
In vmap_pte_range, BUG_ON is called when page is already mapped,
It doesn't give enough information to debug further.
Dumping page owner information alongwith BUG_ON will be more useful
in case of multiple page mapping.
Example:
[ 14.552875] page: refcount:1 mapcount:0 mapping:
0000000000000000 index:0x0 pfn:0x10b923
[ 14.553440] flags: 0xbffff0000000000(node=0|zone=2|lastcpupid=0x3ffff)
[ 14.554001] page_type: 0xffffffff()
[ 14.554783] raw:
0bffff0000000000 0000000000000000 dead000000000122 0000000000000000
[ 14.555230] raw:
0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
[ 14.555768] page dumped because: remapping already mapped page
[ 14.556172] page_owner tracks the page as allocated
[ 14.556482] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid 80 (insmod), ts
14552004992, free_ts 0
[ 14.557286] prep_new_page+0xa8/0x10c
[ 14.558052] get_page_from_freelist+0x7f8/0x1248
[ 14.558298] __alloc_pages+0x164/0x2b4
[ 14.558514] alloc_pages_mpol+0x88/0x230
[ 14.558904] alloc_pages+0x4c/0x7c
[ 14.559157] load_module+0x74/0x1af4
[ 14.559361] __do_sys_init_module+0x190/0x1fc
[ 14.559615] __arm64_sys_init_module+0x1c/0x28
[ 14.559883] invoke_syscall+0x44/0x108
[ 14.560109] el0_svc_common.constprop.0+0x40/0xe0
[ 14.560371] do_el0_svc_compat+0x1c/0x34
[ 14.560600] el0_svc_compat+0x2c/0x80
[ 14.560820] el0t_32_sync_handler+0x90/0x140
[ 14.561040] el0t_32_sync+0x194/0x198
[ 14.561329] page_owner free stack trace missing
[ 14.562049] ------------[ cut here ]------------
[ 14.562314] kernel BUG at mm/vmalloc.c:113!
Link: https://lkml.kernel.org/r/20240424111838.3782931-2-hariom1.p@samsung.com
Signed-off-by: Hariom Panthi <hariom1.p@samsung.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Maninder Singh <maninder1.s@samsung.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rohit Thapliyal <r.thapliyal@samsung.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Wed, 24 Apr 2024 12:26:30 +0000 (14:26 +0200)]
mm/khugepaged: replace page_mapcount() check by folio_likely_mapped_shared()
We want to limit the use of page_mapcount() to places where absolutely
required, to prepare for kernel configs where we won't keep track of
per-page mapcounts in large folios.
khugepaged is one of the remaining "more challenging" page_mapcount()
users, but we might be able to move away from page_mapcount() without
resulting in a significant behavior change that would warrant
special-casing based on kernel configs.
In 2020, we first added support to khugepaged for collapsing COW-shared
pages via commit
9445689f3b61 ("khugepaged: allow to collapse a page
shared across fork"), followed by support for collapsing PTE-mapped THP in
commit
5503fbf2b0b8 ("khugepaged: allow to collapse PTE-mapped compound
pages") and limiting the memory waste via the "page_count() > 1" check in
commit
71a2c112a0f6 ("khugepaged: introduce 'max_ptes_shared' tunable").
As a default, khugepaged will allow up to half of the PTEs to map shared
pages: where page_mapcount() > 1. MADV_COLLAPSE ignores the khugepaged
setting.
khugepaged does currently not care about swapcache page references, and
does not check under folio lock: so in some corner cases the "shared vs.
exclusive" detection might be a bit off, making us detect "exclusive" when
it's actually "shared".
Most of our anonymous folios in the system are usually exclusive. We
frequently see sharing of anonymous folios for a short period of time,
after which our short-lived suprocesses either quit or exec().
There are some famous examples, though, where child processes exist for a
long time, and where memory is COW-shared with a lot of processes
(webservers, webbrowsers, sshd, ...) and COW-sharing is crucial for
reducing the memory footprint. We don't want to suddenly change the
behavior to result in a significant increase in memory waste.
Interestingly, khugepaged will only collapse an anonymous THP if at least
one PTE is writable. After fork(), that means that something (usually a
page fault) populated at least a single exclusive anonymous THP in that
PMD range.
So ... what happens when we switch to "is this folio mapped shared"
instead of "is this page mapped shared" by using
folio_likely_mapped_shared()?
For "not-COW-shared" folios, small folios and for THPs (large folios) that
are completely mapped into at least one process, switching to
folio_likely_mapped_shared() will not result in a change.
We'll only see a change for COW-shared PTE-mapped THPs that are partially
mapped into all involved processes.
There are two cases to consider:
(A) folio_likely_mapped_shared() returns "false" for a PTE-mapped THP
If the folio is detected as exclusive, and it actually is exclusive,
there is no change: page_mapcount() == 1. This is the common case
without fork() or with short-lived child processes.
folio_likely_mapped_shared() might currently still detect a folio as
exclusive although it is shared (false negatives): if the first page is
not mapped multiple times and if the average per-page mapcount is smaller
than 1, implying that (1) the folio is partially mapped and (2) if we are
responsible for many mapcounts by mapping many pages others can't
("mostly exclusive") (3) if we are not responsible for many mapcounts by
mapping little pages ("mostly shared") it won't make a big impact on the
end result.
So while we might now detect a page as "exclusive" although it isn't,
it's not expected to make a big difference in common cases.
(B) folio_likely_mapped_shared() returns "true" for a PTE-mapped THP
folio_likely_mapped_shared() will never detect a large anonymous folio
as shared although it is exclusive: there are no false positives.
If we detect a THP as shared, at least one page of the THP is mapped by
another process. It could well be that some pages are actually exclusive.
For example, our child processes could have unmapped/COW'ed some pages
such that they would now be exclusive to out process, which we now
would treat as still-shared.
Examples:
(1) Parent maps all pages of a THP, child maps some pages. We detect
all pages in the parent as shared although some are actually
exclusive.
(2) Parent maps all but some page of a THP, child maps the remainder.
We detect all pages of the THP that the parent maps as shared
although they are all exclusive.
In (1) we wouldn't collapse a THP right now already: no PTE
is writable, because a write fault would have resulted in COW of a
single page and the parent would no longer map all pages of that THP.
For (2) we would have collapsed a THP in the parent so far, now we
wouldn't as long as the child process is still alive: unless the child
process unmaps the remaining THP pages or we decide to split that THP.
Possibly, the child COW'ed many pages, meaning that it's likely that
we can populate a THP for our child first, and then for our parent.
For (2), we are making really bad use of the THP in the first
place (not even mapped completely in at least one process). If the
THP would be completely partially mapped, it would be on the deferred
split queue where we would split it lazily later.
For short-running child processes, we don't particularly care. For
long-running processes, the expectation is that such scenarios are
rather rare: further, a THP might be best placed if most data in the
PMD range is actually written, implying that we'll have to COW more
pages first before khugepaged would collapse it.
To summarize, in the common case, this change is not expected to matter
much. The more common application of khugepaged operates on exclusive
pages, either before fork() or after a child quit.
Can we improve (A)? Yes, if we implement more precise tracking of "mapped
shared" vs. "mapped exclusively", we could get rid of the false negatives
completely.
Can we improve (B)? We could count how many pages of a large folio we map
inside the current page table and detect that we are responsible for most
of the folio mapcount and conclude "as good as exclusive", which might
help in some cases. ... but likely, some other mechanism should detect
that the THP is not a good use in the scenario (not even mapped completely
in a single process) and try splitting that folio lazily etc.
We'll move the folio_test_anon() check before our "shared" check, so we
might get more expressive results for SCAN_EXCEED_SHARED_PTE: this order
of checks now matches the one in __collapse_huge_page_isolate(). Extend
documentation.
Link: https://lkml.kernel.org/r/20240424122630.495788-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Breno Leitao [Wed, 24 Apr 2024 12:59:39 +0000 (05:59 -0700)]
memcg: fix data-race KCSAN bug in rstats
A data-race issue in memcg rstat occurs when two distinct code paths
access the same 4-byte region concurrently. KCSAN detection triggers the
following BUG as a result.
BUG: KCSAN: data-race in __count_memcg_events / mem_cgroup_css_rstat_flush
write to 0xffffe8ffff98e300 of 4 bytes by task 5274 on cpu 17:
mem_cgroup_css_rstat_flush (mm/memcontrol.c:5850)
cgroup_rstat_flush_locked (kernel/cgroup/rstat.c:243 (discriminator 7))
cgroup_rstat_flush (./include/linux/spinlock.h:401 kernel/cgroup/rstat.c:278)
mem_cgroup_flush_stats.part.0 (mm/memcontrol.c:767)
memory_numa_stat_show (mm/memcontrol.c:6911)
<snip>
read to 0xffffe8ffff98e300 of 4 bytes by task 410848 on cpu 27:
__count_memcg_events (mm/memcontrol.c:725 mm/memcontrol.c:962)
count_memcg_event_mm.part.0 (./include/linux/memcontrol.h:1097 ./include/linux/memcontrol.h:1120)
handle_mm_fault (mm/memory.c:5483 mm/memory.c:5622)
<snip>
value changed: 0x00000029 -> 0x00000000
The race occurs because two code paths access the same "stats_updates"
location. Although "stats_updates" is a per-CPU variable, it is remotely
accessed by another CPU at
cgroup_rstat_flush_locked()->mem_cgroup_css_rstat_flush(), leading to the
data race mentioned.
Considering that memcg_rstat_updated() is in the hot code path, adding a
lock to protect it may not be desirable, especially since this variable
pertains solely to statistics.
Therefore, annotating accesses to stats_updates with READ/WRITE_ONCE() can
prevent KCSAN splats and potential partial reads/writes.
Link: https://lkml.kernel.org/r/20240424125940.2410718-1-leitao@debian.org
Fixes: 9cee7e8ef3e3 ("mm: memcg: optimize parent iteration in memcg_rstat_updated()")
Signed-off-by: Breno Leitao <leitao@debian.org>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:12 +0000 (20:19 +0100)]
mm: remove PageReferenced
All callers now use folio_*_referenced() so we can remove the
PageReferenced family of functions.
Link: https://lkml.kernel.org/r/20240424191914.361554-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:11 +0000 (20:19 +0100)]
mm: add kernel-doc for folio_mark_accessed()
Convert the existing documentation to kernel-doc and remove references to
pages.
Link: https://lkml.kernel.org/r/20240424191914.361554-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:10 +0000 (20:19 +0100)]
gup: use folios for gup_devmap
Use try_grab_folio() instead of try_grab_page() so we get the folio back
that we calculated, and then use folio_set_referenced() instead of
SetPageReferenced(). Correspondingly, use gup_put_folio() to put any
unneeded references.
Link: https://lkml.kernel.org/r/20240424191914.361554-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:09 +0000 (20:19 +0100)]
mm: remove page_ref_sub_return()
With all callers converted to folios, we can act directly on
folio->_refcount.
Link: https://lkml.kernel.org/r/20240424191914.361554-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:08 +0000 (20:19 +0100)]
mm: convert put_devmap_managed_page_refs() to put_devmap_managed_folio_refs()
All callers have a folio so we can remove this use of
page_ref_sub_return().
Link: https://lkml.kernel.org/r/20240424191914.361554-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:07 +0000 (20:19 +0100)]
mm: remove put_devmap_managed_page()
It only has one caller; convert that caller to use
put_devmap_managed_page_refs() instead.
Link: https://lkml.kernel.org/r/20240424191914.361554-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Wed, 24 Apr 2024 19:19:06 +0000 (20:19 +0100)]
mm: remove page_cache_alloc()
Patch series "More folio compat code removal".
More code removal with bonus kernel-doc addition.
This patch (of 7):
All callers have now been converted to filemap_alloc_folio().
Link: https://lkml.kernel.org/r/20240424191914.361554-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240424191914.361554-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 23 Apr 2024 22:55:36 +0000 (23:55 +0100)]
userfault; expand folio use in mfill_atomic_install_pte()
Call page_folio() a little earlier so we can use folio_mapping()
instead of page_mapping(), saving a call to compound_head().
Link: https://lkml.kernel.org/r/20240423225552.4113447-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 23 Apr 2024 22:55:35 +0000 (23:55 +0100)]
migrate: expand the use of folio in __migrate_device_pages()
Removes a few calls to compound_head() and a call to page_mapping().
Link: https://lkml.kernel.org/r/20240423225552.4113447-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 23 Apr 2024 22:55:34 +0000 (23:55 +0100)]
memory-failure: remove calls to page_mapping()
This is mostly just inlining page_mapping() into the two callers.
Link: https://lkml.kernel.org/r/20240423225552.4113447-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 23 Apr 2024 22:55:33 +0000 (23:55 +0100)]
f2fs: convert f2fs_clear_page_cache_dirty_tag to use a folio
Removes uses of page_mapping() and page_index().
Link: https://lkml.kernel.org/r/20240423225552.4113447-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 23 Apr 2024 22:55:32 +0000 (23:55 +0100)]
fscrypt: convert bh_get_inode_and_lblk_num to use a folio
Patch series "Remove page_mapping()".
There are only a few users left. Convert them all to either call
folio_mapping() or just use folio->mapping directly.
This patch (of 6):
Remove uses of page->index, page_mapping() and b_page. Saves a call
to compound_head().
Link: https://lkml.kernel.org/r/20240423225552.4113447-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240423225552.4113447-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:08 +0000 (20:35 +0100)]
mm/memory-failure: pass the folio to collect_procs_ksm()
We've already calculated it, so pass it in instead of recalculating it in
collect_procs_ksm().
Link: https://lkml.kernel.org/r/20240412193510.2356957-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:07 +0000 (20:35 +0100)]
mm/memory-failure: use folio functions throughout collect_procs()
Saves a couple of calls to compound_head().
Link: https://lkml.kernel.org/r/20240412193510.2356957-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:06 +0000 (20:35 +0100)]
mm/memory-failure: add some folio conversions to unpoison_memory
Some of these folio APIs didn't exist when the unpoison_memory()
conversion was done originally.
Link: https://lkml.kernel.org/r/20240412193510.2356957-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:05 +0000 (20:35 +0100)]
mm/memory-failure: convert hwpoison_user_mappings to take a folio
Pass the folio from the callers, and use it throughout instead of hpage.
Saves dozens of calls to compound_head().
Link: https://lkml.kernel.org/r/20240412193510.2356957-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:04 +0000 (20:35 +0100)]
mm/memory-failure: convert memory_failure() to use a folio
Saves dozens of calls to compound_head().
Link: https://lkml.kernel.org/r/20240412193510.2356957-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:03 +0000 (20:35 +0100)]
mm: convert hugetlb_page_mapping_lock_write to folio
The page is only used to get the mapping, so the folio will do just as
well. Both callers already have a folio available, so this saves a call
to compound_head().
Link: https://lkml.kernel.org/r/20240412193510.2356957-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:02 +0000 (20:35 +0100)]
mm/memory-failure: convert shake_page() to shake_folio()
Removes two calls to compound_head(). Move the prototype to internal.h;
we definitely don't want code outside mm using it.
Link: https://lkml.kernel.org/r/20240412193510.2356957-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:01 +0000 (20:35 +0100)]
mm: make page_mapped_in_vma conditional on CONFIG_MEMORY_FAILURE
This function is only currently used by the memory-failure code, so we can
omit it if we're not compiling in the memory-failure code.
Link: https://lkml.kernel.org/r/20240412193510.2356957-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Suggested-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:35:00 +0000 (20:35 +0100)]
mm: return the address from page_mapped_in_vma()
The only user of this function calls page_address_in_vma() immediately
after page_mapped_in_vma() calculates it and uses it to return true/false.
Return the address instead, allowing memory-failure to skip the call to
page_address_in_vma().
Link: https://lkml.kernel.org/r/20240412193510.2356957-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:34:59 +0000 (20:34 +0100)]
mm/memory-failure: pass addr to __add_to_kill()
Handle anon/file folios the same way as KSM & DAX folios by passing in the
address.
Link: https://lkml.kernel.org/r/20240412193510.2356957-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Fri, 12 Apr 2024 19:34:58 +0000 (20:34 +0100)]
mm/memory-failure: remove fsdax_pgoff argument from __add_to_kill
Patch series "Some cleanups for memory-failure", v3.
A lot of folio conversions, plus some other simplifications.
This patch (of 11):
Unify the KSM and DAX codepaths by calculating the addr in
add_to_kill_fsdax() instead of telling __add_to_kill() to calculate it.
Link: https://lkml.kernel.org/r/20240412193510.2356957-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240412193510.2356957-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andy Shevchenko [Tue, 23 Apr 2024 14:20:25 +0000 (17:20 +0300)]
xarray: don't use "proxy" headers
Update header inclusions to follow IWYU (Include What You Use)
principle.
Link: https://lkml.kernel.org/r/20240423142204.2408923-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andy Shevchenko [Tue, 23 Apr 2024 14:20:24 +0000 (17:20 +0300)]
xarray: use BITS_PER_LONGS()
Patch series "xarray: Clean up xarray.h".
Main portion of this change is to get rid of kernel.h included into other
globally available headers. This decreases a dependency hell degree. The
first patch makes it possible to avoid math.h to be included as bitops.h
is implied by bitmap.h.
This patch (of 2):
Use BITS_PER_LONGS() instead of open coded variant.
Link: https://lkml.kernel.org/r/20240423142204.2408923-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Shakeel Butt [Sat, 20 Apr 2024 23:25:05 +0000 (16:25 -0700)]
memcg: simple cleanup of stats update functions
mod_memcg_lruvec_state() is never called from outside of memcontrol.c and
with always irq disabled. So, replace it with the irq disabled version
and add an assert that irq is disabled in the caller.
Similarly mod_objcg_state() is not called from outside of memcontrol.c, so
simply make it static and change it's name to __mod_objcg_state().
Link: https://lkml.kernel.org/r/20240420232505.2768428-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Mon, 22 Apr 2024 03:00:39 +0000 (11:00 +0800)]
mm: memory: check userfaultfd_wp() in vmf_orig_pte_uffd_wp()
Add userfaultfd_wp() check in vmf_orig_pte_uffd_wp() to avoid the
unnecessary FAULT_FLAG_ORIG_PTE_VALID check/pte_marker_entry_uffd_wp() in
most pagefault, note, the function vmf_orig_pte_uffd_wp() is not inlined
in the two kernel versions, the difference is shown below,
perf date,
perf report -i perf.data.before | grep vmf
0.17% 0.13% lat_pagefault [kernel.kallsyms] [k] vmf_orig_pte_uffd_wp.part.0.isra.0
perf report -i perf.data.after | grep vmf
lat_pagefault -W 5 -N 5 /tmp/XXX
latency before after diff
average(8 tests) 0.262675 0.
2600375 -0.
0026375
Although it's a small, but the uffd_wp is a new feature than previous
kernel, when the vma is not registered with UFFD_WP, let's avoid to
execute the new logical, also adding __always_inline attribute to
vmf_orig_pte_uffd_wp(), which make set_pte_range() only check VM_UFFD_WP
flags without the function call. In addition, directly call the
vmf_orig_pte_uffd_wp() in do_anonymous_page() and set_pte_range() to save
an uffd_wp variable.
Link: https://lkml.kernel.org/r/20240422030039.3293568-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hao Ge [Mon, 22 Apr 2024 03:27:25 +0000 (11:27 +0800)]
mm/page-flags: make PageUptodate return bool
Make PageUptodate return bool to align the return values of
folio_test_uptodate function
Link: https://lkml.kernel.org/r/20240422032725.41452-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ruihan Li <lrh2000@pku.edu.cn>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lance Yang [Thu, 18 Apr 2024 13:44:35 +0000 (21:44 +0800)]
mm/madvise: optimize lazyfreeing with mTHP in madvise_free
This patch optimizes lazyfreeing with PTE-mapped mTHP[1] (Inspired by
David Hildenbrand[2]). We aim to avoid unnecessary folio splitting if the
large folio is fully mapped within the target range.
If a large folio is locked or shared, or if we fail to split it, we just
leave it in place and advance to the next PTE in the range. But note that
the behavior is changed; previously, any failure of this sort would cause
the entire operation to give up. As large folios become more common,
sticking to the old way could result in wasted opportunities.
On an Intel I5 CPU, lazyfreeing a 1GiB VMA backed by PTE-mapped folios of
the same size results in the following runtimes for madvise(MADV_FREE) in
seconds (shorter is better):
Folio Size | Old | New | Change
------------------------------------------
4KiB | 0.590251 | 0.590259 | 0%
16KiB | 2.990447 | 0.185655 | -94%
32KiB | 2.547831 | 0.104870 | -95%
64KiB | 2.457796 | 0.052812 | -97%
128KiB | 2.281034 | 0.032777 | -99%
256KiB | 2.230387 | 0.017496 | -99%
512KiB | 2.189106 | 0.010781 | -99%
1024KiB | 2.183949 | 0.007753 | -99%
2048KiB | 0.002799 | 0.002804 | 0%
[1] https://lkml.kernel.org/r/
20231207161211.
2374093-5-ryan.roberts@arm.com
[2] https://lore.kernel.org/linux-mm/
20240214204435.167852-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240418134435.6092-5-ioworker0@gmail.com
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Jeff Xie <xiehuan09@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lance Yang [Thu, 18 Apr 2024 13:44:34 +0000 (21:44 +0800)]
mm/memory: add any_dirty optional pointer to folio_pte_batch()
This commit adds the any_dirty pointer as an optional parameter to
folio_pte_batch() function. By using both the any_young and any_dirty
pointers, madvise_free can make smarter decisions about whether to clear
the PTEs when marking large folios as lazyfree.
Link: https://lkml.kernel.org/r/20240418134435.6092-4-ioworker0@gmail.com
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Jeff Xie <xiehuan09@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lance Yang [Thu, 18 Apr 2024 13:44:33 +0000 (21:44 +0800)]
mm/arm64: override clear_young_dirty_ptes() batch helper
The per-pte get_and_clear/modify/set approach would result in
unfolding/refolding for contpte mappings on arm64. So we need to override
clear_young_dirty_ptes() for arm64 to avoid it.
Link: https://lkml.kernel.org/r/20240418134435.6092-3-ioworker0@gmail.com
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Suggested-by: Barry Song <21cnbao@gmail.com>
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jeff Xie <xiehuan09@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lance Yang [Thu, 18 Apr 2024 13:44:32 +0000 (21:44 +0800)]
mm/madvise: introduce clear_young_dirty_ptes() batch helper
Patch series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free",
v10.
This patchset adds support for lazyfreeing multi-size THP (mTHP) without
needing to first split the large folio via split_folio(). However, we
still need to split a large folio that is not fully mapped within the
target range.
If a large folio is locked or shared, or if we fail to split it, we just
leave it in place and advance to the next PTE in the range. But note that
the behavior is changed; previously, any failure of this sort would cause
the entire operation to give up. As large folios become more common,
sticking to the old way could result in wasted opportunities.
Performance Testing
===================
On an Intel I5 CPU, lazyfreeing a 1GiB VMA backed by PTE-mapped folios of
the same size results in the following runtimes for madvise(MADV_FREE) in
seconds (shorter is better):
Folio Size | Old | New | Change
------------------------------------------
4KiB | 0.590251 | 0.590259 | 0%
16KiB | 2.990447 | 0.185655 | -94%
32KiB | 2.547831 | 0.104870 | -95%
64KiB | 2.457796 | 0.052812 | -97%
128KiB | 2.281034 | 0.032777 | -99%
256KiB | 2.230387 | 0.017496 | -99%
512KiB | 2.189106 | 0.010781 | -99%
1024KiB | 2.183949 | 0.007753 | -99%
2048KiB | 0.002799 | 0.002804 | 0%
This patch (of 4):
This commit introduces clear_young_dirty_ptes() to replace mkold_ptes().
By doing so, we can use the same function for both use cases
(madvise_pageout and madvise_free), and it also provides the flexibility
to only clear the dirty flag in the future if needed.
Link: https://lkml.kernel.org/r/20240418134435.6092-1-ioworker0@gmail.com
Link: https://lkml.kernel.org/r/20240418134435.6092-2-ioworker0@gmail.com
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Jeff Xie <xiehuan09@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Thu, 18 Apr 2024 13:56:44 +0000 (21:56 +0800)]
mm: swapfile: check usable swap device in __folio_throttle_swaprate()
Skip blk_cgroup_congested() if there is no usable swap device since no
swapin/out will occur, Thereby avoid taking swap_lock. The difference
is shown below from perf date of CoW pagefault,
perf report -g -i perf.data.swapon | egrep "blk_cgroup_congested|__folio_throttle_swaprate"
1.01% 0.16% page_fault2_pro [kernel.kallsyms] [k] __folio_throttle_swaprate
0.83% 0.80% page_fault2_pro [kernel.kallsyms] [k] blk_cgroup_congested
perf report -g -i perf.data.swapoff | egrep "blk_cgroup_congested|__folio_throttle_swaprate"
0.15% 0.15% page_fault2_pro [kernel.kallsyms] [k] __folio_throttle_swaprate
Link: https://lkml.kernel.org/r/20240418135644.2736748-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Thu, 18 Apr 2024 15:18:34 +0000 (17:18 +0200)]
mm/huge_memory: improve split_huge_page_to_list_to_order() return value documentation
The documentation is wrong and relying on it almost resulted in BUGs in
new callers: ever since
fd4a7ac32918 ("mm: migrate: try again if THP split
is failed due to page refcnt") we return -EAGAIN on unexpected folio
references, not -EBUSY.
Let's fix that and also document which other return values we can
currently see and why they could happen.
[david@redhat.com: v2]
Link: https://lkml.kernel.org/r/20240422194217.442933-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240418151834.216557-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Wed, 17 Apr 2024 21:25:49 +0000 (17:25 -0400)]
mm/page_table_check: support userfault wr-protect entries
Allow page_table_check hooks to check over userfaultfd wr-protect criteria
upon pgtable updates. The rule is no co-existance allowed for any
writable flag against userfault wr-protect flag.
This should be better than
c2da319c2e, where we used to only sanitize such
issues during a pgtable walk, but when hitting such issue we don't have a
good chance to know where does that writable bit came from [1], so that
even the pgtable walk exposes a kernel bug (which is still helpful on
triaging) but not easy to track and debug.
Now we switch to track the source. It's much easier too with the recent
introduction of page table check.
There are some limitations with using the page table check here for
userfaultfd wr-protect purpose:
- It is only enabled with explicit enablement of page table check configs
and/or boot parameters, but should be good enough to track at least
syzbot issues, as syzbot should enable PAGE_TABLE_CHECK[_ENFORCED] for
x86 [1]. We used to have DEBUG_VM but it's now off for most distros,
while distros also normally not enable PAGE_TABLE_CHECK[_ENFORCED], which
is similar.
- It conditionally works with the ptep_modify_prot API. It will be
bypassed when e.g. XEN PV is enabled, however still work for most of the
rest scenarios, which should be the common cases so should be good
enough.
- Hugetlb check is a bit hairy, as the page table check cannot identify
hugetlb pte or normal pte via trapping at set_pte_at(), because of the
current design where hugetlb maps every layers to pte_t... For example,
the default set_huge_pte_at() can invoke set_pte_at() directly and lose
the hugetlb context, treating it the same as a normal pte_t. So far it's
fine because we have huge_pte_uffd_wp() always equals to pte_uffd_wp() as
long as supported (x86 only). It'll be a bigger problem when we'll
define _PAGE_UFFD_WP differently at various pgtable levels, because then
one huge_pte_uffd_wp() per-arch will stop making sense first.. as of now
we can leave this for later too.
This patch also removes commit
c2da319c2e altogether, as we have something
better now.
[1] https://lore.kernel.org/all/
000000000000dce0530615c89210@google.com/
Link: https://lkml.kernel.org/r/20240417212549.2766883-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Wed, 17 Apr 2024 21:18:36 +0000 (17:18 -0400)]
mm/hugetlb: assert hugetlb_lock in __hugetlb_cgroup_commit_charge
This is similar to __hugetlb_cgroup_uncharge_folio() where it relies on
holding hugetlb_lock. Add the similar assertion like the other one, since
it looks like such things may help some day.
Link: https://lkml.kernel.org/r/20240417211836.2742593-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Wed, 17 Apr 2024 09:23:13 +0000 (11:23 +0200)]
fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios
Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.
While at it, use huge_ptep_get() + pte_page() instead of ptep_get() +
vm_normal_page(), just like we do in pagemap_hugetlb_range().
No functional change intended.
Link: https://lkml.kernel.org/r/20240417092313.753919-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Wed, 17 Apr 2024 09:23:12 +0000 (11:23 +0200)]
fs/proc/task_mmu: convert pagemap_hugetlb_range() to work on folios
Patch series "fs/proc/task_mmu: convert hugetlb functions to work on folis".
Let's convert two more functions, getting rid of two more page_mapcount()
calls.
This patch (of 2):
Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.
While at it, also check for PMD table sharing, like we do in
smaps_hugetlb_range().
No functional change intended, except that we would now detect hugetlb
folios shared via PMD table sharing correctly.
Link: https://lkml.kernel.org/r/20240417092313.753919-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240417092313.753919-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wei Yang [Tue, 16 Apr 2024 01:25:59 +0000 (01:25 +0000)]
mm/sparse: guard the size of mem_section is power of 2
We usually have this check, while commit
2a3cb8baef71 ("mm/sparse: delete
old sparse_init and enable new one") missed to take it.
Link: https://lkml.kernel.org/r/20240416012559.4536-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:52 +0000 (04:17 +0100)]
doc: split buffer.rst out of api-summary.rst
Buffer heads are no longer a generic filesystem API but an optional
filesystem support library. Make the documentation structure reflect
that, and include the fine documentation kept in buffer_head.h. We could
give a better overview of what buffer heads are all about, but my
enthusiasm for documenting it is limited.
[willy@infradead.org: fix kerneldoc warning]
Link: https://lkml.kernel.org/r/20240417015933.453505-1-willy@infradead.org
[akpm@linux-foundation.org: remove newline at EOF]
Link: https://lkml.kernel.org/r/20240416031754.4076917-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:51 +0000 (04:17 +0100)]
buffer: improve bdev_getblk documentation
Add some more information about the state of the buffer_head returned.
Link: https://lkml.kernel.org/r/20240416031754.4076917-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:50 +0000 (04:17 +0100)]
buffer: add kernel-doc for bforget() and __bforget()
Distinguish these functions from brelse() and __brelse().
Link: https://lkml.kernel.org/r/20240416031754.4076917-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:49 +0000 (04:17 +0100)]
buffer: add kernel-doc for brelse() and __brelse()
Move the documentation for __brelse() to brelse(), format it as kernel-doc
and update it from talking about pages to folios.
Link: https://lkml.kernel.org/r/20240416031754.4076917-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:48 +0000 (04:17 +0100)]
buffer: fix __bread and __bread_gfp kernel-doc
The extra indentation confused the kernel-doc parser, so remove it. Fix
some other wording while I'm here, and advise the user they need to call
brelse() on this buffer.
__bread_gfp() isn't used directly by filesystems, but the other wrappers
for it don't have documentation, so document it accordingly.
Link: https://lkml.kernel.org/r/20240416031754.4076917-5-willy@infradead.org
Co-developed-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:47 +0000 (04:17 +0100)]
buffer: add kernel-doc for try_to_free_buffers()
The documentation for this function has become separated from it over
time; move it to the right place and turn it into kernel-doc. Mild
editing of the content to make it more about what the function does, and
less about how it does it.
Link: https://lkml.kernel.org/r/20240416031754.4076917-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:46 +0000 (04:17 +0100)]
buffer: add kernel-doc for block_dirty_folio()
Turn the excellent documentation for this function into kernel-doc.
Replace 'page' with 'folio' and make a few other minor updates.
Link: https://lkml.kernel.org/r/20240416031754.4076917-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 16 Apr 2024 03:17:45 +0000 (04:17 +0100)]
doc: improve the description of __folio_mark_dirty
Patch series "Improve buffer head documentation", v3.
Turn buffer head documentation into its own document, and make many
general improvements to the docs. Obviously there is much more that could
be done. Tested with make htmldocs.
This patch (of 8):
I've learned why it's safe to call __folio_mark_dirty() from
mark_buffer_dirty() without holding the folio lock, so update the
description to explain why.
Link: https://lkml.kernel.org/r/20240416031754.4076917-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240416031754.4076917-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Long Li [Tue, 16 Apr 2024 06:16:28 +0000 (14:16 +0800)]
xarray: inline xas_descend to improve performance
The commit
63b1898fffcd ("XArray: Disallow sibling entries of nodes")
modified the xas_descend function in such a way that it was no longer
being compiled as an inline function, because it increased the size of
xas_descend(), and the compiler no longer optimizes it as inline. This
had a negative impact on performance, xas_descend is called frequently to
traverse downwards in the xarray tree, making it a hot function.
Inlining xas_descend has been shown to significantly improve performance
by approximately 4.95% in the iozone write test.
Machine: Intel(R) Xeon(R) Gold 6240 CPU @ 2.60GHz
#iozone i 0 -i 1 -s 64g -r 16m -f /test/tmptest
Before this patch:
kB reclen write rewrite read reread
67108864 16384
2230080 3637689 6315197 5496027
After this patch:
kB reclen write rewrite read reread
67108864 16384
2340360 3666175 6272401 5460782
Percentage change:
4.95% 0.78% -0.68% -0.64%
This patch introduces inlining to the xas_descend function. While this
change increases the size of lib/xarray.o, the performance gains in
critical workloads make this an acceptable trade-off.
Size comparison before and after patch:
.text .data .bss file
0x3502 0 0 lib/xarray.o.before
0x3602 0 0 lib/xarray.o.after
Link: https://lkml.kernel.org/r/20240416061628.3768901-1-leo.lilong@huawei.com
Signed-off-by: Long Li <leo.lilong@huawei.com>
Cc: Hou Tao <houtao1@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: yangerkun <yangerkun@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 16 Apr 2024 17:25:33 +0000 (19:25 +0200)]
mm/ksm: remove page_mapcount() usage in stable_tree_search()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.
If our folio has a stable node, it is a (small) KSM folio -- see
folio_stable_node(). Let's use folio_mapcount() in stable_tree_search()
instead, which results in no functional change.
The mapcount > 1 check is a bit confusing, because that's usually a check
for page sharing. Looks like the reason is that we are guaranteed to not
exceed ksm_max_page_sharing for the tree KSM folio when merging with that.
Let's update the documentation to make that clearer.
Link: https://lkml.kernel.org/r/20240416172533.663418-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yosry Ahmed [Sat, 13 Apr 2024 02:24:07 +0000 (02:24 +0000)]
mm: zswap: remove same_filled module params
These knobs offer more fine-grained control to userspace than needed and
directly expose/influence kernel implementation; remove them.
For disabling same_filled handling, there is no logical reason to refuse
storing same-filled pages more efficiently and opt for compression.
Scanning pages for patterns may be an argument, but the page contents will
be read into the CPU cache anyway during compression. Also, removing the
same_filled handling code does not move the needle significantly in terms
of performance anyway [1].
For disabling non_same_filled handling, it was added when the compressed
pages in zswap were not being properly charged to memcgs, as workloads
could escape the accounting with compression [2]. This is no longer the
case after commit
f4840ccfca25 ("zswap: memcg accounting"), and using
zswap without compression does not make much sense.
[1]https://lore.kernel.org/lkml/CAJD7tkaySFP2hBQw4pnZHJJwe3bMdjJ1t9VC2VJd=khn1_TXvA@mail.gmail.com/
[2]https://lore.kernel.org/lkml/
19d5cdee-2868-41bd-83d5-
6da75d72e940@maciej.szmigiero.name/
[yosryahmed@google.com: remove same_filled_pages from docs]
Link: https://lkml.kernel.org/r/ZhxFVggdyvCo79jc@google.com
Link: https://lkml.kernel.org/r/20240413022407.785696-5-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yosry Ahmed [Sat, 13 Apr 2024 02:24:06 +0000 (02:24 +0000)]
mm: zswap: move more same-filled pages checks outside of zswap_store()
Currently, zswap_store() checks zswap_same_filled_pages_enabled, kmaps the
folio, then calls zswap_is_page_same_filled() to check the folio contents.
Move this logic into zswap_is_page_same_filled() as well (and rename it
to use 'folio' while we are at it).
This makes zswap_store() cleaner, and makes following changes to that
logic contained within the helper.
While we are at it:
- Rename the insert_entry label to store_entry to match xa_store().
- Add comment headers for same-filled functions and the main API
functions (load, store, invalidate, swapon, swapoff).
No functional change intended.
Link: https://lkml.kernel.org/r/20240413022407.785696-4-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yosry Ahmed [Sat, 13 Apr 2024 02:24:05 +0000 (02:24 +0000)]
mm: zswap: refactor limit checking from zswap_store()
Refactor limit and acceptance threshold checking outside of zswap_store().
This code will be moved around in a following patch, so it would be
cleaner to move a function call around.
Link: https://lkml.kernel.org/r/20240413022407.785696-3-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yosry Ahmed [Sat, 13 Apr 2024 02:24:04 +0000 (02:24 +0000)]
mm: zswap: always shrink in zswap_store() if zswap_pool_reached_full
Patch series "zswap same-filled and limit checking cleanups", v3.
Miscellaneous cleanups for limit checking and same-filled handling in the
store path. This series was broken out of the "zswap: store zero-filled
pages more efficiently" series [1]. It contains the cleanups and drops
the main functional changes.
[1]https://lore.kernel.org/lkml/
20240325235018.
2028408-1-yosryahmed@google.com/
This patch (of 4):
The cleanup code in zswap_store() is not pretty, particularly the 'shrink'
label at the bottom that ends up jumping between cleanup labels.
Instead of having a dedicated label to shrink the pool, just use
zswap_pool_reached_full directly to figure out if the pool needs
shrinking. zswap_pool_reached_full should be true if and only if the pool
needs shrinking.
The only caveat is that the value of zswap_pool_reached_full may be
changed by concurrent zswap_store() calls between checking the limit and
testing zswap_pool_reached_full in the cleanup code. This is fine
because:
- If zswap_pool_reached_full was true during limit checking then became
false during the cleanup code, then someone else already took care of
shrinking the pool and there is no need to queue the worker. That
would be a good change.
- If zswap_pool_reached_full was false during limit checking then became
true during the cleanup code, then someone else hit the limit
meanwhile. In this case, both threads will try to queue the worker,
but it never gets queued more than once anyway. Also, calling
queue_work() multiple times when the limit is hit could already happen
today, so this isn't a significant change in any way.
Link: https://lkml.kernel.org/r/20240413022407.785696-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20240413022407.785696-2-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suren Baghdasaryan [Mon, 15 Apr 2024 02:08:21 +0000 (19:08 -0700)]
userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
When folio is moved with UFFDIO_MOVE it gets locked before the rmap and
index are modified. Due to the folio lock being already held,
WRITE_ONCE() is not needed when setting the folio index. Remove it.
Link: https://lkml.kernel.org/r/20240415020821.1152951-1-surenb@google.com
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Fri, 12 Apr 2024 03:27:04 +0000 (11:27 +0800)]
mm: page_alloc: allowing mTHP compaction to capture the freed page directly
Currently, compaction_capture() does not allow lower-order allocations to
directly capture the movable free pages, even though lower-order
allocations might also be requesting movable pages, that can lead to more
compaction scanning. And, with the enablement of mTHP, such situations
will become more common.
Thus allowing lower-order (mTHP) allocations of movable page types
directly capture the movable free pages can avoid unnecessary compaction
scanning, meanwhile that won't pollute the movable pageblock. With
testing 1M mTHP compaction, it can be seen that compaction scanning is
significantly reduced.
mm-unstable patched
Ops Compaction pages isolated
116598741.00
120946702.00
Ops Compaction migrate scanned
1764870054.00
1488621550.00
Ops Compaction free scanned
7707879039.00
4986299318.00
Ops Compact scan efficiency 22.90 29.85
Ops Compaction cost 73797.69 72933.48
Link: https://lkml.kernel.org/r/8118a5d66a034736a48433beddaca60ed78577c4.1712892329.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Fri, 12 Apr 2024 06:47:51 +0000 (14:47 +0800)]
mm: filemap: batch mm counter updating in filemap_map_pages()
Like copy_pte_range()/zap_pte_range(), make mm counter batch updating in
filemap_map_pages(), since folios type are same(MM_SHMEMPAGES or
MM_FILEPAGES) in filemap_map_pages(), only check the first folio type is
enough, the 'lat_pagefault -P 1 file' test from lmbench shows 12%
improvement, and the percpu_counter_add_batch() is gone from perf flame
graph.
Link: https://lkml.kernel.org/r/20240412064751.119015-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Fri, 12 Apr 2024 06:47:50 +0000 (14:47 +0800)]
mm: move mm counter updating out of set_pte_range()
Patch series "mm: batch mm counter updating in filemap_map_pages()", v3.
Let's batch mm counter updating to accelerate filemap_map_pages().
This patch (of 2):
In order to support batch mm counter updating in filemap_map_pages(), move
mm counter updating out of set_pte_range(), the folios are file from
filemap, and distinguish folios by vmf->flags and vma->vm_flags from
another caller finish_fault().
Link: https://lkml.kernel.org/r/20240412064751.119015-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240412064751.119015-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Barry Song [Fri, 12 Apr 2024 11:48:58 +0000 (23:48 +1200)]
mm: correct the docs for thp_fault_alloc and thp_fault_fallback
The documentation does not align with the code. In
__do_huge_pmd_anonymous_page(), THP_FAULT_FALLBACK is incremented when
mem_cgroup_charge() fails, despite the allocation succeeding, whereas
THP_FAULT_ALLOC is only incremented after a successful charge.
Link: https://lkml.kernel.org/r/20240412114858.407208-5-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Barry Song [Fri, 12 Apr 2024 11:48:57 +0000 (23:48 +1200)]
mm: add docs for per-order mTHP counters and transhuge_page ABI
This patch includes documentation for mTHP counters and an ABI file for
sys-kernel-mm-transparent-hugepage, which appears to have been missing for
some time.
[v-songbaohua@oppo.com: fix the name and unexpected indentation]
Link: https://lkml.kernel.org/r/20240415054538.17071-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240412114858.407208-4-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Barry Song [Fri, 12 Apr 2024 11:48:56 +0000 (23:48 +1200)]
mm: add per-order mTHP anon_swpout and anon_swpout_fallback counters
This helps to display the fragmentation situation of the swapfile, knowing
the proportion of how much we haven't split large folios. So far, we only
support non-split swapout for anon memory, with the possibility of
expanding to shmem in the future. So, we add the "anon" prefix to the
counter names.
Link: https://lkml.kernel.org/r/20240412114858.407208-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Barry Song [Fri, 12 Apr 2024 11:48:55 +0000 (23:48 +1200)]
mm: add per-order mTHP anon_fault_alloc and anon_fault_fallback counters
Patch series "mm: add per-order mTHP alloc and swpout counters", v6.
The patchset introduces a framework to facilitate mTHP counters, starting
with the allocation and swap-out counters. Currently, only four new nodes
are appended to the stats directory for each mTHP size.
/sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
anon_fault_alloc
anon_fault_fallback
anon_fault_fallback_charge
anon_swpout
anon_swpout_fallback
These nodes are crucial for us to monitor the fragmentation levels of both
the buddy system and the swap partitions. In the future, we may consider
adding additional nodes for further insights.
This patch (of 4):
Profiling a system blindly with mTHP has become challenging due to the
lack of visibility into its operations. Presenting the success rate of
mTHP allocations appears to be pressing need.
Recently, I've been experiencing significant difficulty debugging
performance improvements and regressions without these figures. It's
crucial for us to understand the true effectiveness of mTHP in real-world
scenarios, especially in systems with fragmented memory.
This patch establishes the framework for per-order mTHP counters. It
begins by introducing the anon_fault_alloc and anon_fault_fallback
counters. Additionally, to maintain consistency with
thp_fault_fallback_charge in /proc/vmstat, this patch also tracks
anon_fault_fallback_charge when mem_cgroup_charge fails for mTHP.
Incorporating additional counters should now be straightforward as well.
Link: https://lkml.kernel.org/r/20240412114858.407208-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240412114858.407208-2-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sidhartha Kumar [Fri, 12 Apr 2024 18:21:39 +0000 (11:21 -0700)]
mm/hugetlb: rename dissolve_free_huge_pages() to dissolve_free_hugetlb_folios()
dissolve_free_huge_pages() only uses folios internally, rename it to
dissolve_free_hugetlb_folios() and change the comments which reference it.
[akpm@linux-foundation.org: remove unneeded `extern']
Link: https://lkml.kernel.org/r/20240412182139.120871-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sidhartha Kumar [Thu, 11 Apr 2024 16:47:56 +0000 (09:47 -0700)]
mm/hugetlb: convert dissolve_free_huge_pages() to folios
Allows us to rename dissolve_free_huge_pages() to
dissolve_free_hugetlb_folio(). Convert one caller to pass in a folio
directly and use page_folio() to convert the caller in mm/memory-failure.
[sidhartha.kumar@oracle.com: remove unneeded `extern']
Link: https://lkml.kernel.org/r/71760ed4-e80d-493a-95ea-2545414b1aba@oracle.com
[sidhartha.kumar@oracle.com: v2]
Link: https://lkml.kernel.org/r/20240412182139.120871-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20240411164756.261178-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:11 +0000 (14:17 +0800)]
mm/ksm: replace set_page_stable_node by folio_set_stable_node
Only single page could be reached where we set stable node after write
protect, so use folio converted func to replace page's. And remove the
unused func set_page_stable_node().
Link: https://lkml.kernel.org/r/20240411061713.1847574-11-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Thu, 11 Apr 2024 06:17:10 +0000 (14:17 +0800)]
mm/ksm: rename get_ksm_page_flags to ksm_get_folio_flags
As we are removing get_ksm_page_flags(), make the flags match the new
function name.
Link: https://lkml.kernel.org/r/20240411061713.1847574-10-alexs@kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Alex Shi <alexs@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:09 +0000 (14:17 +0800)]
mm/ksm: convert chain series funcs and replace get_ksm_page
In ksm stable tree all page are single, let's convert them to use and
folios as well as stable_tree_insert/stable_tree_search funcs. And
replace get_ksm_page() by ksm_get_folio() since there is no more needs.
It could save a few compound_head calls.
Link: https://lkml.kernel.org/r/20240411061713.1847574-9-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:08 +0000 (14:17 +0800)]
mm/ksm: use folio in write_protect_page
Compound page is checked and skipped before write_protect_page() called,
use folio to save a few compound_head checks.
Link: https://lkml.kernel.org/r/20240411061713.1847574-8-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:07 +0000 (14:17 +0800)]
mm/ksm: use ksm_get_folio in scan_get_next_rmap_item
Save a compound_head call.
Link: https://lkml.kernel.org/r/20240411061713.1847574-7-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:06 +0000 (14:17 +0800)]
mm/ksm: use folio in stable_node_dup
Use ksm_get_folio() and save 2 compound_head calls.
Link: https://lkml.kernel.org/r/20240411061713.1847574-6-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:05 +0000 (14:17 +0800)]
mm/ksm: use folio in remove_stable_node
Pages in stable tree are all single normal page, so uses ksm_get_folio()
and folio_set_stable_node(), also saves 3 calls to compound_head().
Link: https://lkml.kernel.org/r/20240411061713.1847574-5-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:04 +0000 (14:17 +0800)]
mm/ksm: add folio_set_stable_node
Turn set_page_stable_node() into a wrapper folio_set_stable_node, and then
use it to replace the former. we will merge them together after all place
converted to folio.
Link: https://lkml.kernel.org/r/20240411061713.1847574-4-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:03 +0000 (14:17 +0800)]
mm/ksm: use folio in remove_rmap_item_from_tree
To save 2 compound_head calls.
Link: https://lkml.kernel.org/r/20240411061713.1847574-3-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi (tencent) [Thu, 11 Apr 2024 06:17:02 +0000 (14:17 +0800)]
mm/ksm: add ksm_get_folio
Patch series "transfer page to folio in KSM".
This is the first part of page to folio transfer on KSM. Since only
single page could be stored in KSM, we could safely transfer stable tree
pages to folios.
This patchset could reduce ksm.o 57kbytes from
2541776 bytes on latest
akpm/mm-stable branch with CONFIG_DEBUG_VM enabled. It pass the KSM
testing in LTP and kernel selftest.
Thanks for Matthew Wilcox and David Hildenbrand's suggestions and
comments!
This patch (of 10):
The ksm only contains single pages, so we could add a new func
ksm_get_folio for get_ksm_page to use folio instead of pages to save a
couple of compound_head calls.
After all caller replaced, get_ksm_page will be removed.
Link: https://lkml.kernel.org/r/20240411061713.1847574-1-alexs@kernel.org
Link: https://lkml.kernel.org/r/20240411061713.1847574-2-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Thu, 11 Apr 2024 13:09:25 +0000 (21:09 +0800)]
arm: mm: drop VM_FAULT_BADMAP/VM_FAULT_BADACCESS
If bad map or access, directly set code to SEGV_MAPRR or SEGV_ACCERR, also
set fault to 0 and goto error handling, which make us to drop the arch's
special vm fault reason.
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20240411130925.73281-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang [Thu, 11 Apr 2024 13:09:24 +0000 (21:09 +0800)]
arm64: mm: drop VM_FAULT_BADMAP/VM_FAULT_BADACCESS
Patch series "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS", v2.
Directly set SEGV_MAPRR or SEGV_ACCERR for arm/arm64 to remove the last
two arch's private vm_fault reasons.
This patch (of 2):
If bad map or access, directly set si_code to SEGV_MAPRR or SEGV_ACCERR,
also set fault to 0 and goto error handling, which make us to drop the
arch's special vm fault reason.
Link: https://lkml.kernel.org/r/20240411130925.73281-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240411130925.73281-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:23:01 +0000 (21:23 +0200)]
Documentation/admin-guide/cgroup-v1/memory.rst: don't reference page_mapcount()
Let's stop talking about page_mapcount().
Link: https://lkml.kernel.org/r/20240409192301.907377-19-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:23:00 +0000 (21:23 +0200)]
mm/debug: print only page mapcount (excluding folio entire mapcount) in __dump_folio()
Let's simplify and only print the page mapcount: we already print the
large folio mapcount and the entire folio mapcount for large folios
separately; that should be sufficient to figure out what's happening.
While at it, print the page mapcount also if it had an underflow,
filtering out only typed pages.
Link: https://lkml.kernel.org/r/20240409192301.907377-18-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:59 +0000 (21:22 +0200)]
xtensa/mm: convert check_tlb_entry() to sanity check folios
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. So let's convert check_tlb_entry() to perform
sanity checks on folios instead of pages.
This essentially already happened: page_count() is mapped to
folio_ref_count(), and page_mapped() to folio_mapped() internally.
However, we would have printed the page_mapount(), which does not really
match what page_mapped() would have checked.
Let's simply print the folio mapcount to avoid using page_mapcount(). For
small folios there is no change.
Link: https://lkml.kernel.org/r/20240409192301.907377-17-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:58 +0000 (21:22 +0200)]
trace/events/page_ref: trace the raw page mapcount value
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. We already trace raw page->refcount, raw
page->flags and raw page->mapping, and don't involve any folios. Let's
also trace the raw mapcount value that does not consider the entire
mapcount of large folios, and we don't add "1" to it.
When dealing with typed folios, this makes a lot more sense. ... and
it's for debugging purposes only either way.
Link: https://lkml.kernel.org/r/20240409192301.907377-16-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:57 +0000 (21:22 +0200)]
mm/migrate_device: use folio_mapcount() in migrate_vma_check_page()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. Let's convert migrate_vma_check_page() to work on a
folio internally so we can remove the page_mapcount() usage.
Note that we reject any large folios.
There is a lot more folio conversion to be had, but that has to wait for
another day. No functional change intended.
Link: https://lkml.kernel.org/r/20240409192301.907377-15-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:56 +0000 (21:22 +0200)]
mm/filemap: use folio_mapcount() in filemap_unaccount_folio()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.
Let's use folio_mapcount() instead of filemap_unaccount_folio().
No functional change intended, because we're only dealing with small
folios.
Link: https://lkml.kernel.org/r/20240409192301.907377-14-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:55 +0000 (21:22 +0200)]
sh/mm/cache: use folio_mapped() in copy_from_user_page()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.
We're already using folio_mapped in copy_user_highpage() and
copy_to_user_page() for a similar purpose so ... let's also simply use it
for copy_from_user_page().
There is no change for small folios. Likely we won't stumble over many
large folios on sh in that code either way.
Link: https://lkml.kernel.org/r/20240409192301.907377-13-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:54 +0000 (21:22 +0200)]
mm/migrate: use folio_likely_mapped_shared() in add_page_for_migration()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. In add_page_for_migration(), we actually want to
check if the folio is mapped shared, to reject such folios. So let's use
folio_likely_mapped_shared() instead.
For small folios, fully mapped THP, and hugetlb folios, there is no change.
For partially mapped, shared THP, we should now do a better job at
rejecting such folios.
Link: https://lkml.kernel.org/r/20240409192301.907377-12-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:53 +0000 (21:22 +0200)]
mm/page_alloc: use folio_mapped() in __alloc_contig_migrate_range()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.
For tracing purposes, we use page_mapcount() in
__alloc_contig_migrate_range(). Adding that mapcount to total_mapped
sounds strange: total_migrated and total_reclaimed would count each page
only once, not multiple times.
But then, isolate_migratepages_range() adds each folio only once to the
list. So for large folios, we would query the mapcount of the first page
of the folio, which doesn't make too much sense for large folios.
Let's simply use folio_mapped() * folio_nr_pages(), which makes more sense
as nr_migratepages is also incremented by the number of pages in the folio
in case of successful migration.
Link: https://lkml.kernel.org/r/20240409192301.907377-11-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 9 Apr 2024 19:22:52 +0000 (21:22 +0200)]
mm/memory-failure: use folio_mapcount() in hwpoison_user_mappings()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. We can only unmap full folios; page_mapped(), which
we check here, is translated to folio_mapped() -- based on
folio_mapcount(). So let's print the folio mapcount instead.
Link: https://lkml.kernel.org/r/20240409192301.907377-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / linux.git / log