blk-mq: skip CPU offline notify on unmapped hctx

If an hctx has no software ctx mapped, blk_mq_map_swqueue() never
allocates tags and leaves hctx->tags NULL. The CPU hotplug offline
notifier can still run for that hctx, return early since hctx cannot
hold any requests.

Signed-off-by: Cong Zhang <cong.zhang@oss.qualcomm.com>
Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Cong Zhang
2025-12-30 17:17:05 +08:00
committed by Jens Axboe
parent a2ce133969
commit 10845a105b

View File

@@ -3721,7 +3721,7 @@ static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node)
struct blk_mq_hw_ctx, cpuhp_online);
int ret = 0;
if (blk_mq_hctx_has_online_cpu(hctx, cpu))
if (!hctx->nr_ctx || blk_mq_hctx_has_online_cpu(hctx, cpu))
return 0;
/*