From: Chao Leng <lengchao@huawei.com>
To: <linux-nvme@lists.infradead.org>
Cc: kbusch@kernel.org, axboe@fb.com, hch@lst.de, lengchao@huawei.com,
sagi@grimberg.me
Subject: [PATCH] nvme-core: reduce io pause time when fail over
Date: Wed, 22 Jul 2020 17:36:33 +0800 [thread overview]
Message-ID: <20200722093633.31347-1-lengchao@huawei.com> (raw)
We test nvme over roce fail over with multipath when 1000 namespaces
configured, io pause more than 10 seconds. The reason: nvme_stop_queues
will quiesce all queues for each namespace when io timeout cause path
error. Quiesce queue wait all ongoing dispatches finished through
synchronize_rcu, need more than 10 milliseconds for each wait,
thus io pause more than 10 seconds.
To reduce io pause time, nvme_stop_queues use
blk_mq_quiesce_queue_nowait to quiesce the queue, nvme_stop_queues wait
all ongoing dispatches completed after all queues has been quiesced.
Signed-off-by: Chao Leng <lengchao@huawei.com>
---
drivers/nvme/host/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index add040168e67..877dd75d8a8c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4323,8 +4323,9 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl)
down_read(&ctrl->namespaces_rwsem);
list_for_each_entry(ns, &ctrl->namespaces, list)
- blk_mq_quiesce_queue(ns->queue);
+ blk_mq_quiesce_queue_nowait(ns->queue);
up_read(&ctrl->namespaces_rwsem);
+ synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nvme_stop_queues);
--
2.16.4
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next reply other threads:[~2020-07-22 9:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 9:36 Chao Leng [this message]
2020-07-22 16:00 ` [PATCH] nvme-core: reduce io pause time when fail over Keith Busch
2020-07-22 16:13 ` Sagi Grimberg
2020-07-23 8:06 ` Chao Leng
2020-07-23 16:30 ` Sagi Grimberg
2020-07-23 16:42 ` Keith Busch
2020-07-23 19:12 ` Sagi Grimberg
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