diff options
| author | Hugh Dickins <hughd@google.com> | 2018-11-30 14:10:35 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 19:31:57 +0100 |
| commit | ee13d69bc1e8a55bbdfd588190628c54a90b9782 (patch) | |
| tree | 97e99202b885c78f067d0688fe3ecdd036be3ba4 /mm | |
| parent | 78141aabfbb9560c4efcf7599ad0f01575bf0cf3 (diff) | |
mm/khugepaged: collapse_shmem() remember to clear holes
commit 2af8ff291848cc4b1cce24b6c943394eb2c761e8 upstream.
Huge tmpfs testing reminds us that there is no __GFP_ZERO in the gfp
flags khugepaged uses to allocate a huge page - in all common cases it
would just be a waste of effort - so collapse_shmem() must remember to
clear out any holes that it instantiates.
The obvious place to do so, where they are put into the page cache tree,
is not a good choice: because interrupts are disabled there. Leave it
until further down, once success is assured, where the other pages are
copied (before setting PageUptodate).
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261525080.2275@eggly.anvils
Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/khugepaged.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 87dbb0fcfa1a..068868763b78 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1498,7 +1498,12 @@ tree_unlocked: * Replacing old pages with new one has succeed, now we need to * copy the content and free old pages. */ + index = start; list_for_each_entry_safe(page, tmp, &pagelist, lru) { + while (index < page->index) { + clear_highpage(new_page + (index % HPAGE_PMD_NR)); + index++; + } copy_highpage(new_page + (page->index % HPAGE_PMD_NR), page); list_del(&page->lru); @@ -1508,6 +1513,11 @@ tree_unlocked: ClearPageActive(page); ClearPageUnevictable(page); put_page(page); + index++; + } + while (index < end) { + clear_highpage(new_page + (index % HPAGE_PMD_NR)); + index++; } local_irq_save(flags); |