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authorDaniel Wagner <dwagner@suse.de>2020-11-30 11:19:21 +0100
committerJens Axboe <axboe@kernel.dk>2020-12-16 14:55:25 -0700
commite6582cb5dab4ae572513412cc10fd0ffe07e0b05 (patch)
tree3fab7bf8fbd54271236438fc5e32ccfbfdafd754
parent009bd55dfcc857d8b00a5bbb17a8db060317af6f (diff)
downloadlinux-e6582cb5dab4ae572513412cc10fd0ffe07e0b05.tar.bz2
blk-mq: Remove 'running from the wrong CPU' warning
It's guaranteed that no request is in flight when a hctx is going offline. This warning is only triggered when the wq's CPU is hot plugged and the blk-mq is not synced up yet. As this state is temporary and the request is still processed correctly, better remove the warning as this is the fast path. Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-mq.c25
1 files changed, 0 insertions, 25 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b09ce00cc6af..a428798e1c5c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1496,31 +1496,6 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
int srcu_idx;
/*
- * We should be running this queue from one of the CPUs that
- * are mapped to it.
- *
- * There are at least two related races now between setting
- * hctx->next_cpu from blk_mq_hctx_next_cpu() and running
- * __blk_mq_run_hw_queue():
- *
- * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(),
- * but later it becomes online, then this warning is harmless
- * at all
- *
- * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(),
- * but later it becomes offline, then the warning can't be
- * triggered, and we depend on blk-mq timeout handler to
- * handle dispatched requests to this hctx
- */
- if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
- cpu_online(hctx->next_cpu)) {
- printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n",
- raw_smp_processor_id(),
- cpumask_empty(hctx->cpumask) ? "inactive": "active");
- dump_stack();
- }
-
- /*
* We can't run the queue inline with ints disabled. Ensure that
* we catch bad users of this early.
*/