diff options
| author | Andrea Arcangeli <aarcange@redhat.com> | 2015-11-05 18:49:10 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:57:17 +0200 |
| commit | 90da749f224bec8b37810e160aa1b8eed5c4e0b2 (patch) | |
| tree | cd17d35526dcea0ef1f33f694f9a58f563c19f17 /include/linux/raid_class.h | |
| parent | bc2dd250fe9d1b2034b66a3d9ead632946966503 (diff) | |
ksm: don't fail stable tree lookups if walking over stale stable_nodes
The stable_nodes can become stale at any time if the underlying pages gets
freed. The stable_node gets collected and removed from the stable rbtree
if that is detected during the rbtree lookups.
Don't fail the lookup if running into stale stable_nodes, just restart the
lookup after collecting the stale stable_nodes. Otherwise the CPU spent
in the preparation stage is wasted and the lookup must be repeated at the
next loop potentially failing a second time in a second stale stable_node.
If we don't prune aggressively we delay the merging of the unstable node
candidates and at the same time we delay the freeing of the stale
stable_nodes. Keeping stale stable_nodes around wastes memory and it
can't provide any benefit.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Petr Holasek <pholasek@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Joe Maples <joe@frap129.org>
Diffstat (limited to 'include/linux/raid_class.h')
0 files changed, 0 insertions, 0 deletions