blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
authorJens Axboe <axboe@fb.com>
Mon, 24 Nov 2014 22:02:42 +0000 (15:02 -0700)
committerJens Axboe <axboe@fb.com>
Mon, 24 Nov 2014 22:02:42 +0000 (15:02 -0700)
We currently use num_possible_cpus(), but that breaks on sparc64 where
the CPU ID space is discontig. Use nr_cpu_ids as the highest CPU ID
instead, so we don't end up reading from invalid memory.

Cc: stable@kernel.org # 3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-mq-cpumap.c

index 1065d7c65fa15b60b1104944322533033df69df7..72e5ed691e37ae38eadf606bf0d017308c3e48bc 100644 (file)
@@ -90,7 +90,7 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
        unsigned int *map;
 
        /* If cpus are offline, map them to first hctx */
-       map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL,
+       map = kzalloc_node(sizeof(*map) * nr_cpu_ids, GFP_KERNEL,
                                set->numa_node);
        if (!map)
                return NULL;