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| author | Mikulas Patocka <mpatocka@redhat.com> | 2014-10-01 13:29:48 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-14 08:59:51 -0800 |
| commit | 7f6c5d82bf5bb50bb3d836f5b0f207e0afeadeba (patch) | |
| tree | b234dfe4522fe48ffcfbbce5d63868c8f503250d /include/linux/tty_ldisc.h | |
| parent | 07321b43e0a6695d39b5ebb7633960a3f89e138f (diff) | |
| download | lwn-7f6c5d82bf5bb50bb3d836f5b0f207e0afeadeba.tar.gz lwn-7f6c5d82bf5bb50bb3d836f5b0f207e0afeadeba.zip | |
dm bufio: when done scanning return from __scan immediately
commit 0e825862f3c04cee40e25f55680333728a4ffa9b upstream.
When __scan frees the required number of buffer entries that the
shrinker requested (nr_to_scan becomes zero) it must return. Before
this fix the __scan code exited only the inner loop and continued in the
outer loop -- which could result in reduced performance due to extra
buffers being freed (e.g. unnecessarily evicted thinp metadata needing
to be synchronously re-read into bufio's cache).
Also, move dm_bufio_cond_resched to __scan's inner loop, so that
iterating the bufio client's lru lists doesn't result in scheduling
latency.
Reported-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/tty_ldisc.h')
0 files changed, 0 insertions, 0 deletions