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| author | Dave Chinner <dchinner@redhat.com> | 2011-07-08 14:14:34 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-01 12:26:55 -0700 |
| commit | 5e5b3d2ed3aee6f8bbe38c0945876aacce11ff03 (patch) | |
| tree | 16b91161462ffbc0c838973343ea32e504827f19 /mm | |
| parent | 564ea9dd5ab042cb2fe8373f4d627073706e1d4f (diff) | |
| download | lwn-5e5b3d2ed3aee6f8bbe38c0945876aacce11ff03.tar.gz lwn-5e5b3d2ed3aee6f8bbe38c0945876aacce11ff03.zip | |
vmscan: add shrink_slab tracepoints
commit 095760730c1047c69159ce88021a7fa3833502c8 upstream.
Stable note: This patch makes later patches easier to apply but otherwise
has little to justify it. It is a diagnostic patch that was part
of a series addressing excessive slab shrinking after GFP_NOFS
failures. There is detailed information on the series' motivation
at https://lkml.org/lkml/2011/6/2/42 .
It is impossible to understand what the shrinkers are actually doing
without instrumenting the code, so add a some tracepoints to allow
insight to be gained.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmscan.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 6b0f8a60ca68..abc798167cf2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -250,6 +250,7 @@ unsigned long shrink_slab(struct shrink_control *shrink, unsigned long long delta; unsigned long total_scan; unsigned long max_pass; + int shrink_ret = 0; max_pass = do_shrinker_shrink(shrinker, shrink, 0); delta = (4 * nr_pages_scanned) / shrinker->seeks; @@ -274,9 +275,12 @@ unsigned long shrink_slab(struct shrink_control *shrink, total_scan = shrinker->nr; shrinker->nr = 0; + trace_mm_shrink_slab_start(shrinker, shrink, total_scan, + nr_pages_scanned, lru_pages, + max_pass, delta, total_scan); + while (total_scan >= SHRINK_BATCH) { long this_scan = SHRINK_BATCH; - int shrink_ret; int nr_before; nr_before = do_shrinker_shrink(shrinker, shrink, 0); @@ -293,6 +297,8 @@ unsigned long shrink_slab(struct shrink_control *shrink, } shrinker->nr += total_scan; + trace_mm_shrink_slab_end(shrinker, shrink_ret, total_scan, + shrinker->nr); } up_read(&shrinker_rwsem); out: |