mm: hugetlb: change to return bool for isolate_hugetlb()

Now the isolate_hugetlb() only returns 0 or -EBUSY, and most users did not
care about the negative value, thus we can convert the isolate_hugetlb()
to return a boolean value to make code more clear when checking the
hugetlb isolation state.  Moreover converts 2 users which will consider
the negative value returned by isolate_hugetlb().

No functional changes intended.

[akpm@linux-foundation.org: shorten locked section, per SeongJae Park]
Link: https://lkml.kernel.org/r/12a287c5bebc13df304387087bbecc6421510849.1676424378.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index df6dd624ccfe8afc0837c4669bfed9d6e933c1d0..5f5e4177b2e0c38dfcb7492360248cbc744294f2 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -171,7 +171,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
                                                vm_flags_t vm_flags);
 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
                                                long freed);
-int isolate_hugetlb(struct folio *folio, struct list_head *list);
+bool isolate_hugetlb(struct folio *folio, struct list_head *list);
 int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
 int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
                                bool *migratable_cleared);
@@ -413,9 +413,9 @@ static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
        return NULL;
 }
 
-static inline int isolate_hugetlb(struct folio *folio, struct list_head *list)
+static inline bool isolate_hugetlb(struct folio *folio, struct list_head *list)
 {
-       return -EBUSY;
+       return false;
 }
 
 static inline int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3a01a9dbf445a33f886aa2a23af60a1c97817cbe..07abcb6eb203044e39ed9cb839023774c53f3a8a 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2925,12 +2925,15 @@ retry:
                 */
                goto free_new;
        } else if (folio_ref_count(old_folio)) {
+               bool isolated;
+
                /*
                 * Someone has grabbed the folio, try to isolate it here.
                 * Fail with -EBUSY if not possible.
                 */
                spin_unlock_irq(&hugetlb_lock);
-               ret = isolate_hugetlb(old_folio, list);
+               isolated = isolate_hugetlb(old_folio, list);
+               ret = isolated ? 0 : -EBUSY;
                spin_lock_irq(&hugetlb_lock);
                goto free_new;
        } else if (!folio_test_hugetlb_freed(old_folio)) {
@@ -3005,7 +3008,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
        if (hstate_is_gigantic(h))
                return -ENOMEM;
 
-       if (folio_ref_count(folio) && !isolate_hugetlb(folio, list))
+       if (folio_ref_count(folio) && isolate_hugetlb(folio, list))
                ret = 0;
        else if (!folio_ref_count(folio))
                ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
@@ -7251,15 +7254,15 @@ __weak unsigned long hugetlb_mask_last_page(struct hstate *h)
  * These functions are overwritable if your architecture needs its own
  * behavior.
  */
-int isolate_hugetlb(struct folio *folio, struct list_head *list)
+bool isolate_hugetlb(struct folio *folio, struct list_head *list)
 {
-       int ret = 0;
+       bool ret = true;
 
        spin_lock_irq(&hugetlb_lock);
        if (!folio_test_hugetlb(folio) ||
            !folio_test_hugetlb_migratable(folio) ||
            !folio_try_get(folio)) {
-               ret = -EBUSY;
+               ret = false;
                goto unlock;
        }
        folio_clear_hugetlb_migratable(folio);

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e504362fdb23508d003e7045d2a89bebef5932ce..8604753bc6444999d197c20d0c3d413098fa2ff8 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2508,7 +2508,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
        bool isolated = false;
 
        if (PageHuge(page)) {
-               isolated = !isolate_hugetlb(page_folio(page), pagelist);
+               isolated = isolate_hugetlb(page_folio(page), pagelist);
        } else {
                bool lru = !__PageMovable(page);
 

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 2751bc3310fd67da2f81acff4a6567a3f67bd158..a256a241fd1dae8d54abb08d866fa1000773c796 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -609,7 +609,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
        if (flags & (MPOL_MF_MOVE_ALL) ||
            (flags & MPOL_MF_MOVE && folio_estimated_sharers(folio) == 1 &&
             !hugetlb_pmd_shared(pte))) {
-               if (isolate_hugetlb(folio, qp->pagelist) &&
+               if (!isolate_hugetlb(folio, qp->pagelist) &&
                        (flags & MPOL_MF_STRICT))
                        /*
                         * Failed to isolate folio but allow migrating pages

diff --git a/mm/migrate.c b/mm/migrate.c
index 53010a142e7feba7774bee05e57439d17f5e1965..2db546a0618cdd0494ecf0c49768e7c40d7fcee4 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2095,6 +2095,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
        struct vm_area_struct *vma;
        struct page *page;
        int err;
+       bool isolated;
 
        mmap_read_lock(mm);
        err = -EFAULT;
@@ -2126,13 +2127,11 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
 
        if (PageHuge(page)) {
                if (PageHead(page)) {
-                       err = isolate_hugetlb(page_folio(page), pagelist);
-                       if (!err)
-                               err = 1;
+                       isolated = isolate_hugetlb(page_folio(page), pagelist);
+                       err = isolated ? 1 : -EBUSY;
                }
        } else {
                struct page *head;
-               bool isolated;
 
                head = compound_head(page);
                isolated = isolate_lru_page(head);