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| author | Hugh Dickins <hughd@google.com> | 2018-11-30 14:10:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-11-30 14:56:15 -0800 |
| commit | 95feeabb77149f7d48f05bde61d75621c57db67e (patch) | |
| tree | feb93071531a60ec390ac4b18d37cf2c1358b68b /mm/khugepaged.c | |
| parent | 06a5e1268a5fb9c2b346a3da6b97e85f2eba0f07 (diff) | |
| download | linux-95feeabb77149f7d48f05bde61d75621c57db67e.tar.gz linux-95feeabb77149f7d48f05bde61d75621c57db67e.tar.bz2 linux-95feeabb77149f7d48f05bde61d75621c57db67e.zip | |
mm/khugepaged: fix the xas_create_range() error path
collapse_shmem()'s xas_nomem() is very unlikely to fail, but it is
rightly given a failure path, so move the whole xas_create_range() block
up before __SetPageLocked(new_page): so that it does not need to
remember to unlock_page(new_page).
Add the missing mem_cgroup_cancel_charge(), and set (currently unused)
result to SCAN_FAIL rather than SCAN_SUCCEED.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261531200.2275@eggly.anvils
Fixes: 77da9389b9d5 ("mm: Convert collapse_shmem to XArray")
Signed-off-by: Hugh Dickins <hughd@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 2c5fe4f7a0c6..8e2ff195ecb3 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1329,6 +1329,20 @@ static void collapse_shmem(struct mm_struct *mm, goto out; } + /* This will be less messy when we use multi-index entries */ + do { + xas_lock_irq(&xas); + xas_create_range(&xas); + if (!xas_error(&xas)) + break; + xas_unlock_irq(&xas); + if (!xas_nomem(&xas, GFP_KERNEL)) { + mem_cgroup_cancel_charge(new_page, memcg, true); + result = SCAN_FAIL; + goto out; + } + } while (1); + __SetPageLocked(new_page); __SetPageSwapBacked(new_page); new_page->index = start; @@ -1340,17 +1354,6 @@ static void collapse_shmem(struct mm_struct *mm, * be able to map it or use it in another way until we unlock it. */ - /* This will be less messy when we use multi-index entries */ - do { - xas_lock_irq(&xas); - xas_create_range(&xas); - if (!xas_error(&xas)) - break; - xas_unlock_irq(&xas); - if (!xas_nomem(&xas, GFP_KERNEL)) - goto out; - } while (1); - xas_set(&xas, start); for (index = start; index < end; index++) { struct page *page = xas_next(&xas); |