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author | Vlastimil Babka <vbabka@suse.cz> | 2013-09-12 01:22:35 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-12 02:58:01 +0400 |
commit | 7a8010cd36273ff5f6fea5201ef9232f30cebbd9 (patch) | |
tree | 3805f3d9a8a1f1c1c555ef31bc1bdb51fb51e33e /mm/page-writeback.c | |
parent | 5b40998ae35cf64561868370e6c9f3d3e94b6bf7 (diff) | |
download | linux-7a8010cd36273ff5f6fea5201ef9232f30cebbd9.tar.xz |
mm: munlock: manual pte walk in fast path instead of follow_page_mask()
Currently munlock_vma_pages_range() calls follow_page_mask() to obtain
each individual struct page. This entails repeated full page table
translations and page table lock taken for each page separately.
This patch avoids the costly follow_page_mask() where possible, by
iterating over ptes within single pmd under single page table lock. The
first pte is obtained by get_locked_pte() for non-THP page acquired by the
initial follow_page_mask(). The rest of the on-stack pagevec for munlock
is filled up using pte_walk as long as pte_present() and vm_normal_page()
are sufficient to obtain the struct page.
After this patch, a 14% speedup was measured for munlocking a 56GB large
memory area with THP disabled.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jörn Engel <joern@logfs.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
0 files changed, 0 insertions, 0 deletions