dm-stats can be used with very large number of entries (it is only limited
by 1/4 of total system memory), so we should add rescheduling points to
the loops that iterate over the entries.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/md/dm-stats.c | 8 ++++++++
1 file changed, 8 insertions(+)
Index: linux-2.6/drivers/md/dm-stats.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-stats.c 2022-04-24 18:51:25.000000000 +0200
+++ linux-2.6/drivers/md/dm-stats.c 2022-04-24 18:51:25.000000000 +0200
@@ -225,6 +225,7 @@ 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);
}
@@ -330,6 +331,7 @@ 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) {
@@ -342,6 +344,7 @@ 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();
}
}
@@ -362,6 +365,7 @@ 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();
}
}
}
@@ -497,6 +501,7 @@ static int dm_stats_list(struct dm_stats
}
DMEMIT("\n");
}
+ cond_resched();
}
mutex_unlock(&stats->mutex);
@@ -774,6 +779,7 @@ static void __dm_stat_clear(struct dm_st
local_irq_enable();
}
}
+ cond_resched();
}
}
@@ -889,6 +895,8 @@ static int dm_stats_print(struct dm_stat
if (unlikely(sz + 1 >= maxlen))
goto buffer_overflow;
+
+ cond_resched();
}
if (clear)
--
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