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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
8f9cde23c3
commit
72a9826b45
|
@ -690,8 +690,8 @@ 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,
|
||||
|
@ -710,8 +710,8 @@ 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;
|
||||
|
@ -733,7 +733,7 @@ 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);
|
||||
|
@ -773,7 +773,7 @@ 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;
|
||||
|
@ -789,7 +789,7 @@ 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;
|
||||
|
|
Loading…
Reference in a new issue