From: Mikulas Patocka mpatocka@redhat.com
commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream.
dm-stats can be used with a very large number of entries (it is only limited by 1/4 of total system memory), so add rescheduling points to the loops that iterate over the entries.
Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-stats.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -228,6 +228,7 @@ void dm_stats_cleanup(struct dm_stats *s atomic_read(&shared->in_flight[READ]), atomic_read(&shared->in_flight[WRITE])); } + cond_resched(); } dm_stat_free(&s->rcu_head); } @@ -316,6 +317,7 @@ static int dm_stats_create(struct dm_sta for (ni = 0; ni < n_entries; ni++) { atomic_set(&s->stat_shared[ni].in_flight[READ], 0); atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0); + cond_resched(); }
if (s->n_histogram_entries) { @@ -328,6 +330,7 @@ static int dm_stats_create(struct dm_sta for (ni = 0; ni < n_entries; ni++) { s->stat_shared[ni].tmp.histogram = hi; hi += s->n_histogram_entries + 1; + cond_resched(); } }
@@ -348,6 +351,7 @@ static int dm_stats_create(struct dm_sta for (ni = 0; ni < n_entries; ni++) { p[ni].histogram = hi; hi += s->n_histogram_entries + 1; + cond_resched(); } } } @@ -477,6 +481,7 @@ static int dm_stats_list(struct dm_stats } DMEMIT("\n"); } + cond_resched(); } mutex_unlock(&stats->mutex);
@@ -753,6 +758,7 @@ static void __dm_stat_clear(struct dm_st local_irq_enable(); } } + cond_resched(); } }
@@ -868,6 +874,8 @@ static int dm_stats_print(struct dm_stat
if (unlikely(sz + 1 >= maxlen)) goto buffer_overflow; + + cond_resched(); }
if (clear)