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| author | Andrea Arcangeli | 2010-08-10 02:19:08 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2010-08-10 05:44:58 +0200 |
| commit | ba6f0ff3981e6263ab81ac512f04cca55b85ec81 (patch) | |
| tree | 0052d4551de72731be503c8d78949a330ba865ed /Documentation/nommu-mmap.txt | |
| parent | rmap: always add new vmas at the end (diff) | |
| download | kernel-qcow2-linux-ba6f0ff3981e6263ab81ac512f04cca55b85ec81.tar.gz kernel-qcow2-linux-ba6f0ff3981e6263ab81ac512f04cca55b85ec81.tar.xz kernel-qcow2-linux-ba6f0ff3981e6263ab81ac512f04cca55b85ec81.zip | |
ksm: fix ksm swapin time optimization
The new anon-vma code, was suboptimal and it lead to erratic invocation of
ksm_does_need_to_copy. That leads to host hangs or guest vnc lockup, or
weird behavior. It's unclear why ksm_does_need_to_copy is unstable but
the point is that when KSM is not in use, ksm_does_need_to_copy must never
run or we bounce pages for no good reason. I suspect the same hangs will
happen with KVM swaps. But this at least fixes the regression in the
new-anon-vma code and it only let KSM bugs triggers when KSM is in use.
The code in do_swap_page likely doesn't cope well with a not-swapcache,
especially the memcg code.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Izik Eidus <ieidus@yahoo.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/nommu-mmap.txt')
0 files changed, 0 insertions, 0 deletions