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dm stats: add cond_resched when looping over entries

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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>
This commit is contained in:
Mikulas Patocka 2022-04-24 16:43:00 -04:00 committed by Greg Kroah-Hartman
parent 4617778417
commit e39b536d70
1 changed files with 8 additions and 0 deletions
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8
drivers/md/dm-stats.c
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@ -224,6 +224,7 @@ void dm_stats_cleanup(struct dm_stats *stats)
atomic_read(&shared->in_flight[READ]),
atomic_read(&shared->in_flight[WRITE]));
}
cond_resched();
}
dm_stat_free(&s->rcu_head);
}
@ -313,6 +314,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
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) {
@ -325,6 +327,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
for (ni = 0; ni < n_entries; ni++) {
s->stat_shared[ni].tmp.histogram = hi;
hi += s->n_histogram_entries + 1;
cond_resched();
}
}
@ -345,6 +348,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
for (ni = 0; ni < n_entries; ni++) {
p[ni].histogram = hi;
hi += s->n_histogram_entries + 1;
cond_resched();
}
}
}
@ -474,6 +478,7 @@ static int dm_stats_list(struct dm_stats *stats, const char *program,
}
DMEMIT("\n");
}
cond_resched();
}
mutex_unlock(&stats->mutex);
@ -750,6 +755,7 @@ static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
local_irq_enable();
}
}
cond_resched();
}
}
@ -865,6 +871,8 @@ static int dm_stats_print(struct dm_stats *stats, int id,
if (unlikely(sz + 1 >= maxlen))
goto buffer_overflow;
cond_resched();
}
if (clear)