| Message ID | 1516375212.3190.4.camel@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 1/19/18 8:20 AM, Bart Van Assche wrote: > On Fri, 2018-01-19 at 15:26 +0800, Ming Lei wrote: >> Please see queue_delayed_work_on(), hctx->run_work is shared by all >> scheduling, once blk_mq_delay_run_hw_queue(100ms) returns, no new >> scheduling can make progress during the 100ms. > > How about addressing that as follows: > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index f7515dd95a36..57f8379a476d 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1403,9 +1403,9 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, > put_cpu(); > } > > - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > - &hctx->run_work, > - msecs_to_jiffies(msecs)); > + kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > + &hctx->run_work, > + msecs_to_jiffies(msecs)); > } Exactly. That's why I said it was just a bug in my previous email, not honoring a newer run is just stupid. Only other thing you have to be careful with here is the STOPPED bit.
On Fri, Jan 19, 2018 at 03:20:13PM +0000, Bart Van Assche wrote: > On Fri, 2018-01-19 at 15:26 +0800, Ming Lei wrote: > > Please see queue_delayed_work_on(), hctx->run_work is shared by all > > scheduling, once blk_mq_delay_run_hw_queue(100ms) returns, no new > > scheduling can make progress during the 100ms. > > How about addressing that as follows: > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index f7515dd95a36..57f8379a476d 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1403,9 +1403,9 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, > put_cpu(); > } > > - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > - &hctx->run_work, > - msecs_to_jiffies(msecs)); > + kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > + &hctx->run_work, > + msecs_to_jiffies(msecs)); > } > > void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) > > Bart. Yes, this one together with Jen's suggestion with returning BLK_STS_NO_DEV_RESOURCE should fix this issue. Could you cook a fix for this issue? Otherwise I am happy to do that.
On Fri, 2018-01-19 at 23:33 +0800, Ming Lei wrote: > On Fri, Jan 19, 2018 at 03:20:13PM +0000, Bart Van Assche wrote: > > On Fri, 2018-01-19 at 15:26 +0800, Ming Lei wrote: > > > Please see queue_delayed_work_on(), hctx->run_work is shared by all > > > scheduling, once blk_mq_delay_run_hw_queue(100ms) returns, no new > > > scheduling can make progress during the 100ms. > > > > How about addressing that as follows: > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index f7515dd95a36..57f8379a476d 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -1403,9 +1403,9 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, > > put_cpu(); > > } > > > > - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > > - &hctx->run_work, > > - msecs_to_jiffies(msecs)); > > + kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), > > + &hctx->run_work, > > + msecs_to_jiffies(msecs)); > > } > > > > void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) > > > > Bart. > > Yes, this one together with Jen's suggestion with returning > BLK_STS_NO_DEV_RESOURCE should fix this issue. > > Could you cook a fix for this issue? Otherwise I am happy to do > that. Hello Ming, I will look further into this. Bart.
diff --git a/block/blk-mq.c b/block/blk-mq.c index f7515dd95a36..57f8379a476d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1403,9 +1403,9 @@ static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, put_cpu(); } - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), - &hctx->run_work, - msecs_to_jiffies(msecs)); + kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), + &hctx->run_work, + msecs_to_jiffies(msecs)); } void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)