Commit Graph

1 Commits

Author SHA1 Message Date
Baoquan He
e5769870b1 Stop maximizing the bitmap buffer to reduce the risk of OOM.
This is a backport of the following upstream commit.

commit 0b732828091a545185ad13d0b2e6800600788d61
Author: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Date:   Tue Jun 10 13:57:29 2014 +0900

    [PATCH 3/3] Stop maximizing the bitmap buffer to reduce the risk of OOM.

    We tried to maximize the bitmap buffer to get the best performance,
    but the performance degradation caused by multi-cycle processing
    looks very small according to the benchmark on 2TB memory:

      https://lkml.org/lkml/2013/3/26/914

    This result means we don't need to make an effort to maximize the
    bitmap buffer, it will just increase the risk of OOM.

    This patch sets a small fixed value (4MB) as a safety limit,
    it may be safer and enough in most cases.

    Signed-off-by: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-07-16 14:57:21 +08:00