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| author | Seth Jennings <sjenning@linux.vnet.ibm.com> | 2011-12-30 10:42:15 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-08 14:14:14 -0800 |
| commit | 2a4830110b90deb4ee99b1ab8c8ebb120f27c0c8 (patch) | |
| tree | 642f3ddca90439ff7fff2b76474319de2525807c | |
| parent | a9d3c9e3c575ee09c905e07ae7cc1d52e2548d05 (diff) | |
| download | linux-3.10-2a4830110b90deb4ee99b1ab8c8ebb120f27c0c8.tar.gz linux-3.10-2a4830110b90deb4ee99b1ab8c8ebb120f27c0c8.tar.bz2 linux-3.10-2a4830110b90deb4ee99b1ab8c8ebb120f27c0c8.zip | |
staging: zcache: fix serialization bug in zv stats
In a multithreaded workload, the zv_curr_dist_counts
and zv_cumul_dist_counts statistics are being corrupted
because the increments and decrements in zv_create
and zv_free are not atomic.
This patch converts these statistics and their corresponding
increments/decrements/reads to atomic operations.
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/zcache/zcache-main.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index ce07087750a..ef7c52bb1df 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -654,8 +654,8 @@ static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7; */ static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5; -static unsigned long zv_curr_dist_counts[NCHUNKS]; -static unsigned long zv_cumul_dist_counts[NCHUNKS]; +static atomic_t zv_curr_dist_counts[NCHUNKS]; +static atomic_t zv_cumul_dist_counts[NCHUNKS]; static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, struct tmem_oid *oid, uint32_t index, @@ -674,8 +674,8 @@ static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id, &page, &offset, ZCACHE_GFP_MASK); if (unlikely(ret)) goto out; - zv_curr_dist_counts[chunks]++; - zv_cumul_dist_counts[chunks]++; + atomic_inc(&zv_curr_dist_counts[chunks]); + atomic_inc(&zv_cumul_dist_counts[chunks]); zv = kmap_atomic(page, KM_USER0) + offset; zv->index = index; zv->oid = *oid; @@ -697,7 +697,7 @@ static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) ASSERT_SENTINEL(zv, ZVH); BUG_ON(chunks >= NCHUNKS); - zv_curr_dist_counts[chunks]--; + atomic_dec(&zv_curr_dist_counts[chunks]); size -= sizeof(*zv); BUG_ON(size == 0); INVERT_SENTINEL(zv, ZVH); @@ -737,7 +737,7 @@ static int zv_curr_dist_counts_show(char *buf) char *p = buf; for (i = 0; i < NCHUNKS; i++) { - n = zv_curr_dist_counts[i]; + n = atomic_read(&zv_curr_dist_counts[i]); p += sprintf(p, "%lu ", n); chunks += n; sum_total_chunks += i * n; @@ -753,7 +753,7 @@ static int zv_cumul_dist_counts_show(char *buf) char *p = buf; for (i = 0; i < NCHUNKS; i++) { - n = zv_cumul_dist_counts[i]; + n = atomic_read(&zv_cumul_dist_counts[i]); p += sprintf(p, "%lu ", n); chunks += n; sum_total_chunks += i * n; |