summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorHugh Dickins <hughd@google.com>2018-11-30 14:10:35 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-05 19:42:37 +0100
commit5c0ecc2ba54201881c54a51ead083bba85176a76 (patch)
tree362c58874356bead89f6aa27dc99f879d719d9db /mm
parent0dba3e54920bc876aaf88060358d96093b5e7c83 (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.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 3f7bfd98b0e6..2d3ce49f6b45 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1501,7 +1501,12 @@ 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);
@@ -1511,6 +1516,11 @@ 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);