From: Weiping Zhang <zhangweiping@didiglobal.com>
To: <axboe@kernel.dk>, <bvanassche@acm.org>, <tom.leiming@gmail.com>
Cc: <linux-block@vger.kernel.org>
Subject: [PATCH] block: update hctx map when use multiple maps
Date: Wed, 17 Jun 2020 14:18:37 +0800 [thread overview]
Message-ID: <20200617061830.GA15100@192.168.3.9> (raw)
There is an issue when tune the number for read and write queues,
if the total queue count was not changed. The hctx->type cannot
be updated, since __blk_mq_update_nr_hw_queues will return directly
if the total queue count has not been changed.
Reproduce:
dmesg | grep "default/read/poll"
[ 2.607459] nvme nvme0: 48/0/0 default/read/poll queues
cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
48 default
tune the write queues to 24:
echo 24 > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller
dmesg | grep "default/read/poll"
[ 433.547235] nvme nvme0: 24/24/0 default/read/poll queues
cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c
48 default
The driver's hardware queue mapping is not same as block layer.
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4f57d27bfa73..a9aa6d1e44cf 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3479,7 +3479,9 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids)
nr_hw_queues = nr_cpu_ids;
- if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
+ if (nr_hw_queues < 1)
+ return;
+ if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues)
return;
list_for_each_entry(q, &set->tag_list, tag_set_list)
--
2.18.2
next reply other threads:[~2020-06-17 6:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 6:18 Weiping Zhang [this message]
2020-06-18 2:49 ` [PATCH] block: update hctx map when use multiple maps Ming Lei
2020-06-18 3:33 ` Jens Axboe
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