diff options
| author | Prakash Surya <[email protected]> | 2013-12-11 12:25:30 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2014-02-21 14:53:08 -0800 |
| commit | 39e055c44b3025d9ef87f6c6178ef5ae5e2a55c6 (patch) | |
| tree | a4b3581ed1870fdc33a6d38446420a9c9e5e3240 | |
| parent | 914158259225d9723bbb288457797936b41d3c9a (diff) | |
Adjust arc_p based on "bytes" in arc_shrink
In an attempt to prevent arc_c from collapsing "too fast", the
arc_shrink() function was updated to take a "bytes" parameter by this
change:
commit 302f753f1657c05a4287226eeda1f53ae431b8a7
Author: Brian Behlendorf <[email protected]>
Date: Tue Mar 13 14:29:16 2012 -0700
Integrate ARC more tightly with Linux
Unfortunately, that change failed to make a similar change to the way
that arc_p was updated. So, there still exists the possibility for arc_p
to collapse to near 0 when the kernel start calling the arc's shrinkers.
This change attempts to fix this, by decrementing arc_p by the "bytes"
parameter in the same way that arc_c is updated.
In addition, a minimum value of arc_p is attempted to be maintained,
similar to the way a minimum arc_p value is maintained in arc_adapt().
Signed-off-by: Prakash Surya <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #2110
| -rw-r--r-- | module/zfs/arc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 11839af59..cbc9b9fee 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -2332,6 +2332,7 @@ void arc_shrink(uint64_t bytes) { if (arc_c > arc_c_min) { + uint64_t arc_p_min; uint64_t to_free; to_free = bytes ? bytes : arc_c >> zfs_arc_shrink_shift; @@ -2341,7 +2342,14 @@ arc_shrink(uint64_t bytes) else arc_c = arc_c_min; - atomic_add_64(&arc_p, -(arc_p >> zfs_arc_shrink_shift)); + arc_p_min = (arc_c >> zfs_arc_p_min_shift); + to_free = bytes ? bytes : arc_p >> zfs_arc_shrink_shift; + + if (arc_p > arc_p_min + to_free) + atomic_add_64(&arc_p, -to_free); + else + arc_p = arc_p_min; + if (arc_c > arc_size) arc_c = MAX(arc_size, arc_c_min); if (arc_p > arc_c) |