We run a test that delete and recover devcies frequently(two devices on
the same host), and we found that 'active_queues' is super big after a
period of time.
If device a and device b share a tag set, and a is deleted, then
blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
is only one queue that are using the tag set. However, if b is still
active, the active_queues of b might never be cleared even if b is
deleted.
Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
Signed-off-by: Yu Kuai <[email protected]>
---
block/blk-mq.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2c4ac51e54eb..2fe396385a4a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2994,10 +2994,12 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared)
int i;
queue_for_each_hw_ctx(q, hctx, i) {
- if (shared)
+ if (shared) {
hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
- else
+ } else {
+ blk_mq_tag_idle(hctx);
hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
+ }
}
}
--
2.31.1
On 2021/07/31 14:21, Yu Kuai wrote:
> We run a test that delete and recover devcies frequently(two devices on
> the same host), and we found that 'active_queues' is super big after a
> period of time.
>
> If device a and device b share a tag set, and a is deleted, then
> blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
> is only one queue that are using the tag set. However, if b is still
> active, the active_queues of b might never be cleared even if b is
> deleted.
>
> Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
>
> Signed-off-by: Yu Kuai <[email protected]>
> ---
> block/blk-mq.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 2c4ac51e54eb..2fe396385a4a 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2994,10 +2994,12 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared)
> int i;
>
> queue_for_each_hw_ctx(q, hctx, i) {
> - if (shared)
> + if (shared) {
> hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
> - else
> + } else {
> + blk_mq_tag_idle(hctx);
> hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
> + }
> }
> }
>
>
ping...
On Sat, Jul 31, 2021 at 02:21:30PM +0800, Yu Kuai wrote:
> We run a test that delete and recover devcies frequently(two devices on
> the same host), and we found that 'active_queues' is super big after a
> period of time.
>
> If device a and device b share a tag set, and a is deleted, then
> blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
> is only one queue that are using the tag set. However, if b is still
> active, the active_queues of b might never be cleared even if b is
> deleted.
>
> Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
>
> Signed-off-by: Yu Kuai <[email protected]>
> ---
> block/blk-mq.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 2c4ac51e54eb..2fe396385a4a 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2994,10 +2994,12 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared)
> int i;
>
> queue_for_each_hw_ctx(q, hctx, i) {
> - if (shared)
> + if (shared) {
> hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
> - else
> + } else {
> + blk_mq_tag_idle(hctx);
> hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
> + }
> }
> }
Looks correct, the only remained queue in tagset has to be idled before
clearing BLK_MQ_F_TAG_QUEUE_SHARED:
Reviewed-by: Ming Lei <[email protected]>
Thanks,
Ming
Hi, jens
Can you please consider to apply this patch.
By the way, sorry about the wrong email I replied.
Thanks
Kuai
On 2021/08/06 10:25, Ming Lei wrote:
> On Sat, Jul 31, 2021 at 02:21:30PM +0800, Yu Kuai wrote:
>> We run a test that delete and recover devcies frequently(two devices on
>> the same host), and we found that 'active_queues' is super big after a
>> period of time.
>>
>> If device a and device b share a tag set, and a is deleted, then
>> blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
>> is only one queue that are using the tag set. However, if b is still
>> active, the active_queues of b might never be cleared even if b is
>> deleted.
>>
>> Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
>>
>> Signed-off-by: Yu Kuai <[email protected]>
>> ---
>> block/blk-mq.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>> index 2c4ac51e54eb..2fe396385a4a 100644
>> --- a/block/blk-mq.c
>> +++ b/block/blk-mq.c
>> @@ -2994,10 +2994,12 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared)
>> int i;
>>
>> queue_for_each_hw_ctx(q, hctx, i) {
>> - if (shared)
>> + if (shared) {
>> hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
>> - else
>> + } else {
>> + blk_mq_tag_idle(hctx);
>> hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
>> + }
>> }
>> }
>
> Looks correct, the only remained queue in tagset has to be idled before
> clearing BLK_MQ_F_TAG_QUEUE_SHARED:
>
> Reviewed-by: Ming Lei <[email protected]>
>
>
>
> Thanks,
> Ming
>
> .
>
On 7/31/21 12:21 AM, Yu Kuai wrote:
> We run a test that delete and recover devcies frequently(two devices on
> the same host), and we found that 'active_queues' is super big after a
> period of time.
>
> If device a and device b share a tag set, and a is deleted, then
> blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
> is only one queue that are using the tag set. However, if b is still
> active, the active_queues of b might never be cleared even if b is
> deleted.
>
> Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
Applied, thanks.
--
Jens Axboe