From: Cannon Matthews <cannonmatthews@google.com>
Date: Fri, 17 Aug 2018 22:49:17 +0000 (-0700)
Subject: mm/hugetlb.c: don't zero 1GiB bootmem pages
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=330d6e489a0ab49136561d7f792b1d81bcdbb83c;p=linux.git

mm/hugetlb.c: don't zero 1GiB bootmem pages

When using 1GiB pages during early boot, use the new
memblock_virt_alloc_try_nid_raw() to allocate memory without zeroing it.
Zeroing out hundreds or thousands of GiB in a single core memset() call
is very slow, and can make early boot last upwards of 20-30 minutes on
multi TiB machines.

The memory does not need to be zero'd as the hugetlb pages are always
zero'd on page fault.

Tested: Booted with ~3800 1G pages, and it booted successfully in
roughly the same amount of time as with 0, as opposed to the 25+ minutes
it would take before.

Link: http://lkml.kernel.org/r/20180711213313.92481-1-cannonmatthews@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4cea30ac50338..47566bb0b4b12 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2101,7 +2101,7 @@ int __alloc_bootmem_huge_page(struct hstate *h)
 	for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
 		void *addr;
 
-		addr = memblock_virt_alloc_try_nid_nopanic(
+		addr = memblock_virt_alloc_try_nid_raw(
 				huge_page_size(h), huge_page_size(h),
 				0, BOOTMEM_ALLOC_ACCESSIBLE, node);
 		if (addr) {
@@ -2119,6 +2119,7 @@ int __alloc_bootmem_huge_page(struct hstate *h)
 found:
 	BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
 	/* Put them into a private list first because mem_map is not up yet */
+	INIT_LIST_HEAD(&m->list);
 	list_add(&m->list, &huge_boot_pages);
 	m->hstate = h;
 	return 1;