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authorDavid Rientjes <rientjes@google.com>2009-10-15 02:20:22 -0700
committerPekka Enberg <penberg@cs.helsinki.fi>2009-10-15 21:34:12 +0300
commit78eb00cc574d3dbf8e6bed804948a89e8110a064 (patch)
treec0cefa5b5787bb234ba8931775da2071c908e071 /mm/slub.c
parent374576a8b6f865022c0fd1ca62396889b23d66dd (diff)
downloadop-kernel-dev-78eb00cc574d3dbf8e6bed804948a89e8110a064.zip
op-kernel-dev-78eb00cc574d3dbf8e6bed804948a89e8110a064.tar.gz
slub: allow stats to be cleared
When collecting slub stats for particular workloads, it's necessary to collect each statistic for all caches before the job is even started because the counters are usually greater than zero just from boot and initialization. This allows a statistic to be cleared on each cpu by writing '0' to its sysfs file. This creates a baseline for statistics of interest before the workload is started. Setting a statistic to a particular value is not supported, so all values written to these files other than '0' returns -EINVAL. Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 4996fc7..ac0ca4c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4371,12 +4371,28 @@ static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
return len + sprintf(buf + len, "\n");
}
+static void clear_stat(struct kmem_cache *s, enum stat_item si)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ get_cpu_slab(s, cpu)->stat[si] = 0;
+}
+
#define STAT_ATTR(si, text) \
static ssize_t text##_show(struct kmem_cache *s, char *buf) \
{ \
return show_stat(s, buf, si); \
} \
-SLAB_ATTR_RO(text); \
+static ssize_t text##_store(struct kmem_cache *s, \
+ const char *buf, size_t length) \
+{ \
+ if (buf[0] != '0') \
+ return -EINVAL; \
+ clear_stat(s, si); \
+ return length; \
+} \
+SLAB_ATTR(text); \
STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
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