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author | Ebru Akagunduz <ebru.akagunduz@gmail.com> | 2016-07-27 00:25:03 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 01:19:19 +0200 |
commit | 8a966ed746d63c8103d496da85973eeeec01d77f (patch) | |
tree | a96bcdb72409c34910440549c2e4fa248a468c4e /mm/internal.h | |
parent | mm: make optimistic check for swapin readahead (diff) | |
download | linux-8a966ed746d63c8103d496da85973eeeec01d77f.tar.xz linux-8a966ed746d63c8103d496da85973eeeec01d77f.zip |
mm: make swapin readahead to improve thp collapse rate
This patch makes swapin readahead to improve thp collapse rate. When
khugepaged scanned pages, there can be a few of the pages in swap area.
With the patch THP can collapse 4kB pages into a THP when there are up
to max_ptes_swap swap ptes in a 2MB range.
The patch was tested with a test program that allocates 400B of memory,
writes to it, and then sleeps. I force the system to swap out all.
Afterwards, the test program touches the area by writing, it skips a
page in each 20 pages of the area.
Without the patch, system did not swap in readahead. THP rate was %65
of the program of the memory, it did not change over time.
With this patch, after 10 minutes of waiting khugepaged had collapsed
%99 of the program's memory.
[kirill.shutemov@linux.intel.com: trivial cleanup of exit path of the function]
[kirill.shutemov@linux.intel.com: __collapse_huge_page_swapin(): drop unused 'pte' parameter]
[kirill.shutemov@linux.intel.com: do not hold anon_vma lock during swap in]
Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/internal.h')
-rw-r--r-- | mm/internal.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h index fbfba0cc2c35..e1531758122b 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -36,6 +36,10 @@ /* Do not use these with a slab allocator */ #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) +extern int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, pte_t *page_table, pmd_t *pmd, + unsigned int flags, pte_t orig_pte); + void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long floor, unsigned long ceiling); |