]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
ksm: break cow once unshared
authorHugh Dickins <hugh.dickins@tiscali.co.uk>
Tue, 22 Sep 2009 00:02:12 +0000 (17:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Sep 2009 14:17:32 +0000 (07:17 -0700)
commit26465d3ea5a62d59efb3796b9e0e2b0656d02cb1
tree40644bae6d246a1ee0d38b98a5281a3a879725a1
parent473b0ce4d13ee77925a7062e25dea0d16a91f654
ksm: break cow once unshared

We kept agreeing not to bother about the unswappable shared KSM pages
which later become unshared by others: observation suggests they're not
a significant proportion.  But they are disadvantageous, and it is easier
to break COW to replace them by swappable pages, than offer statistics
to show that they don't matter; then we can stop worrying about them.

Doing this in ksm_do_scan, they don't go through cmp_and_merge_page on
this pass: give them a good chance of getting into the unstable tree
on the next pass, or back into the stable, by computing checksum now.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/ksm.c