* [PATCH] block: update hctx map when use multiple maps
@ 2020-06-17 6:18 Weiping Zhang
2020-06-18 2:49 ` Ming Lei
2020-06-18 3:33 ` Jens Axboe
0 siblings, 2 replies; 3+ messages in thread
From: Weiping Zhang @ 2020-06-17 6:18 UTC (permalink / raw)
To: axboe, bvanassche, tom.leiming; +Cc: linux-block
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] block: update hctx map when use multiple maps
2020-06-17 6:18 [PATCH] block: update hctx map when use multiple maps Weiping Zhang
@ 2020-06-18 2:49 ` Ming Lei
2020-06-18 3:33 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Ming Lei @ 2020-06-18 2:49 UTC (permalink / raw)
To: axboe, bvanassche, tom.leiming, linux-block
On Wed, Jun 17, 2020 at 02:18:37PM +0800, Weiping Zhang wrote:
> 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
>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
--
Ming
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] block: update hctx map when use multiple maps
2020-06-17 6:18 [PATCH] block: update hctx map when use multiple maps Weiping Zhang
2020-06-18 2:49 ` Ming Lei
@ 2020-06-18 3:33 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Jens Axboe @ 2020-06-18 3:33 UTC (permalink / raw)
To: bvanassche, tom.leiming, linux-block
On 6/17/20 12:18 AM, Weiping Zhang wrote:
> 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.
Applied, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-06-18 3:33 UTC | newest]
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2020-06-17 6:18 [PATCH] block: update hctx map when use multiple maps Weiping Zhang
2020-06-18 2:49 ` Ming Lei
2020-06-18 3:33 ` Jens Axboe
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