Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 01/19/18 07:24, Jens Axboe wrote: That's what I thought. So for a low queue depth underlying queue, it's quite possible that this situation can happen. Two potential solutions I see: 1) As described earlier in this thread, having a mechanism for being notified when the scarce resource

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 01/19/18 07:24, Jens Axboe wrote: That's what I thought. So for a low queue depth underlying queue, it's quite possible that this situation can happen. Two potential solutions I see: 1) As described earlier in this thread, having a mechanism for being notified when the scarce resource

Re: [PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, 2018-01-23 at 10:22 +0100, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 5:20pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > > And yet Laurence cannot reproduce any such lockups with your test... > > > > Hmm ...

Re: [PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, 2018-01-23 at 10:22 +0100, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 5:20pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > > And yet Laurence cannot reproduce any such lockups with your test... > > > > Hmm ... maybe I misunderstood

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23 2018 at 7:17am -0500, Ming Lei wrote: > On Tue, Jan 23, 2018 at 8:15 PM, Mike Snitzer wrote: > > On Tue, Jan 23 2018 at 5:53am -0500, > > Ming Lei wrote: > > > >> Hi Mike, > >> > >> On Tue, Jan 23, 2018 at

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23 2018 at 7:17am -0500, Ming Lei wrote: > On Tue, Jan 23, 2018 at 8:15 PM, Mike Snitzer wrote: > > On Tue, Jan 23 2018 at 5:53am -0500, > > Ming Lei wrote: > > > >> Hi Mike, > >> > >> On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: > >> > > >> > From: Mike Snitzer

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23, 2018 at 8:15 PM, Mike Snitzer wrote: > On Tue, Jan 23 2018 at 5:53am -0500, > Ming Lei wrote: > >> Hi Mike, >> >> On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: >> > On Thu, Jan 18 2018 at 5:20pm -0500, >> > Bart Van

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23, 2018 at 8:15 PM, Mike Snitzer wrote: > On Tue, Jan 23 2018 at 5:53am -0500, > Ming Lei wrote: > >> Hi Mike, >> >> On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: >> > On Thu, Jan 18 2018 at 5:20pm -0500, >> > Bart Van Assche wrote: >> > >> > > On Thu, 2018-01-18

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23 2018 at 5:53am -0500, Ming Lei wrote: > Hi Mike, > > On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: > > On Thu, Jan 18 2018 at 5:20pm -0500, > > Bart Van Assche wrote: > > > > > On Thu, 2018-01-18 at 17:01 -0500,

Re: block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Tue, Jan 23 2018 at 5:53am -0500, Ming Lei wrote: > Hi Mike, > > On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: > > On Thu, Jan 18 2018 at 5:20pm -0500, > > Bart Van Assche wrote: > > > > > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > > > And yet Laurence

Re: [PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

Hi Mike, On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 5:20pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > > And yet Laurence cannot reproduce any such lockups with your test...

Re: [PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

Hi Mike, On Tue, Jan 23, 2018 at 10:22:04AM +0100, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 5:20pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > > And yet Laurence cannot reproduce any such lockups with your test... > > > > Hmm ... maybe

[PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Thu, Jan 18 2018 at 5:20pm -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > And yet Laurence cannot reproduce any such lockups with your test... > > Hmm ... maybe I misunderstood Laurence but I don't think that Laurence has >

[PATCH] block: neutralize blk_insert_cloned_request IO stall regression (was: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle)

On Thu, Jan 18 2018 at 5:20pm -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > > And yet Laurence cannot reproduce any such lockups with your test... > > Hmm ... maybe I misunderstood Laurence but I don't think that Laurence has > already succeeded at

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 4:52 PM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: >> On 1/19/18 9:37 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 4:52 PM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: >> On 1/19/18 9:37 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:23:35AM -0700, Jens Axboe wrote: > On 1/19/18 9:13 AM, Mike Snitzer wrote: > > On Fri, Jan 19 2018 at 10:48am -0500, > > Jens Axboe wrote: > > > >> On 1/19/18 8:40 AM, Ming Lei wrote: > >> Where does the dm STS_RESOURCE error usually come from -

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:23:35AM -0700, Jens Axboe wrote: > On 1/19/18 9:13 AM, Mike Snitzer wrote: > > On Fri, Jan 19 2018 at 10:48am -0500, > > Jens Axboe wrote: > > > >> On 1/19/18 8:40 AM, Ming Lei wrote: > >> Where does the dm STS_RESOURCE error usually come from - what's exact >

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 15:34 +0800, Ming Lei wrote: > Could you explain a bit when SCSI target replies with BUSY very often? > > Inside initiator, we have limited the max per-LUN requests and per-host > requests already before calling .queue_rq(). That's correct. However, when a SCSI initiator

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 15:34 +0800, Ming Lei wrote: > Could you explain a bit when SCSI target replies with BUSY very often? > > Inside initiator, we have limited the max per-LUN requests and per-host > requests already before calling .queue_rq(). That's correct. However, when a SCSI initiator

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 12:38pm -0500, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> > >> There are no pending requests for this case, nothing to restart the > >> queue. When you fail that

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 12:38pm -0500, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> > >> There are no pending requests for this case, nothing to restart the > >> queue. When you fail that blk_get_request(), you are

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:38:41AM -0700, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: >> On 1/19/18 9:26 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: >> On 1/19/18 9:26 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:09:11AM -0700, Jens Axboe wrote: > On 1/19/18 10:05 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:47 AM, Mike Snitzer wrote: > >>> On Fri, Jan 19 2018 at 11:41am -0500, > >>> Jens Axboe wrote: >

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 10:09:11AM -0700, Jens Axboe wrote: > On 1/19/18 10:05 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:47 AM, Mike Snitzer wrote: > >>> On Fri, Jan 19 2018 at 11:41am -0500, > >>> Jens Axboe wrote: > >>> > On

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 10:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: >> On 1/19/18 9:47 AM, Mike Snitzer wrote: >>> On Fri, Jan 19 2018 at 11:41am -0500, >>> Jens Axboe wrote: >>> On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 10:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: >> On 1/19/18 9:47 AM, Mike Snitzer wrote: >>> On Fri, Jan 19 2018 at 11:41am -0500, >>> Jens Axboe wrote: >>> On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:27:46AM

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: > On 1/19/18 9:47 AM, Mike Snitzer wrote: > > On Fri, Jan 19 2018 at 11:41am -0500, > > Jens Axboe wrote: > > > >> On 1/19/18 9:37 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: >

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:52:32AM -0700, Jens Axboe wrote: > On 1/19/18 9:47 AM, Mike Snitzer wrote: > > On Fri, Jan 19 2018 at 11:41am -0500, > > Jens Axboe wrote: > > > >> On 1/19/18 9:37 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > On 1/19/18

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:47 AM, Mike Snitzer wrote: > On Fri, Jan 19 2018 at 11:41am -0500, > Jens Axboe wrote: > >> On 1/19/18 9:37 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:47 AM, Mike Snitzer wrote: > On Fri, Jan 19 2018 at 11:41am -0500, > Jens Axboe wrote: > >> On 1/19/18 9:37 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:19:24AM -0700,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 11:41am -0500, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > >> > >>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 11:41am -0500, Jens Axboe wrote: > On 1/19/18 9:37 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:26 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > >> > >> There are no pending

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: >> On 1/19/18 9:26 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:37 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: >> On 1/19/18 9:26 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > On 1/19/18 9:26 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:05 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > On 1/19/18 8:40 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:27:46AM -0700, Jens Axboe wrote: > On 1/19/18 9:26 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > >> On 1/19/18 9:05 AM, Ming Lei wrote: > >>> On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > On 1/19/18 8:40 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: >> On 1/19/18 9:05 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: On 1/19/18 8:40 AM, Ming Lei wrote: Where does the dm STS_RESOURCE error usually

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:26 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: >> On 1/19/18 9:05 AM, Ming Lei wrote: >>> On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: On 1/19/18 8:40 AM, Ming Lei wrote: Where does the dm STS_RESOURCE error usually

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > >> On 1/19/18 8:40 AM, Ming Lei wrote: > >> Where does the dm STS_RESOURCE error usually come from - what's exact > >>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 09:19:24AM -0700, Jens Axboe wrote: > On 1/19/18 9:05 AM, Ming Lei wrote: > > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > >> On 1/19/18 8:40 AM, Ming Lei wrote: > >> Where does the dm STS_RESOURCE error usually come from - what's exact > >>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:13 AM, Mike Snitzer wrote: > On Fri, Jan 19 2018 at 10:48am -0500, > Jens Axboe wrote: > >> On 1/19/18 8:40 AM, Ming Lei wrote: >> Where does the dm STS_RESOURCE error usually come from - what's exact >> resource are we running out of? > > It is from

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:13 AM, Mike Snitzer wrote: > On Fri, Jan 19 2018 at 10:48am -0500, > Jens Axboe wrote: > >> On 1/19/18 8:40 AM, Ming Lei wrote: >> Where does the dm STS_RESOURCE error usually come from - what's exact >> resource are we running out of? > > It is from

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: >> On 1/19/18 8:40 AM, Ming Lei wrote: >> Where does the dm STS_RESOURCE error usually come from - what's exact >> resource are we running out of? > > It is from

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 9:05 AM, Ming Lei wrote: > On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: >> On 1/19/18 8:40 AM, Ming Lei wrote: >> Where does the dm STS_RESOURCE error usually come from - what's exact >> resource are we running out of? > > It is from

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 10:48am -0500, Jens Axboe wrote: > On 1/19/18 8:40 AM, Ming Lei wrote: > Where does the dm STS_RESOURCE error usually come from - what's exact > resource are we running out of? > >>> > >>> It is from blk_get_request(underlying queue), see > >>>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19 2018 at 10:48am -0500, Jens Axboe wrote: > On 1/19/18 8:40 AM, Ming Lei wrote: > Where does the dm STS_RESOURCE error usually come from - what's exact > resource are we running out of? > >>> > >>> It is from blk_get_request(underlying queue), see > >>>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 23:33 +0800, Ming Lei wrote: > On Fri, Jan 19, 2018 at 03:20:13PM +, 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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 23:33 +0800, Ming Lei wrote: > On Fri, Jan 19, 2018 at 03:20:13PM +, 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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > On 1/19/18 8:40 AM, Ming Lei wrote: > Where does the dm STS_RESOURCE error usually come from - what's exact > resource are we running out of? > >>> > >>> It is from blk_get_request(underlying queue), see > >>>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 08:48:55AM -0700, Jens Axboe wrote: > On 1/19/18 8:40 AM, Ming Lei wrote: > Where does the dm STS_RESOURCE error usually come from - what's exact > resource are we running out of? > >>> > >>> It is from blk_get_request(underlying queue), see > >>>

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 8:40 AM, Ming Lei wrote: Where does the dm STS_RESOURCE error usually come from - what's exact resource are we running out of? >>> >>> It is from blk_get_request(underlying queue), see >>> multipath_clone_and_map(). >> >> That's what I thought. So for a low queue depth

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 8:40 AM, Ming Lei wrote: Where does the dm STS_RESOURCE error usually come from - what's exact resource are we running out of? >>> >>> It is from blk_get_request(underlying queue), see >>> multipath_clone_and_map(). >> >> That's what I thought. So for a low queue depth

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 08:24:06AM -0700, Jens Axboe wrote: > On 1/19/18 12:26 AM, Ming Lei wrote: > > On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: > >> On 1/18/18 7:32 PM, Ming Lei wrote: > >>> On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > On 1/18/18 11:47 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 08:24:06AM -0700, Jens Axboe wrote: > On 1/19/18 12:26 AM, Ming Lei wrote: > > On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: > >> On 1/18/18 7:32 PM, Ming Lei wrote: > >>> On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > On 1/18/18 11:47 AM,

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 03:20:13PM +, 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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 03:20:13PM +, 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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 12:26 AM, Ming Lei wrote: > On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: >> On 1/18/18 7:32 PM, Ming Lei wrote: >>> On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: On 1/18/18 11:47 AM, Bart Van Assche wrote: >> This is all very tiresome. > >

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/19/18 12:26 AM, Ming Lei wrote: > On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: >> On 1/18/18 7:32 PM, Ming Lei wrote: >>> On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: On 1/18/18 11:47 AM, Bart Van Assche wrote: >> This is all very tiresome. > >

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

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

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 05:09:46AM +, Bart Van Assche wrote: > On Fri, 2018-01-19 at 10:32 +0800, Ming Lei wrote: > > Now most of times both NVMe and SCSI won't return BLK_STS_RESOURCE, and > > it should be DM-only which returns STS_RESOURCE so often. > > That's wrong at least for SCSI. See

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, Jan 19, 2018 at 05:09:46AM +, Bart Van Assche wrote: > On Fri, 2018-01-19 at 10:32 +0800, Ming Lei wrote: > > Now most of times both NVMe and SCSI won't return BLK_STS_RESOURCE, and > > it should be DM-only which returns STS_RESOURCE so often. > > That's wrong at least for SCSI. See

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: > On 1/18/18 7:32 PM, Ming Lei wrote: > > On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > >> On 1/18/18 11:47 AM, Bart Van Assche wrote: > This is all very tiresome. > >>> > >>> Yes, this is tiresome. It is very

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18, 2018 at 09:02:45PM -0700, Jens Axboe wrote: > On 1/18/18 7:32 PM, Ming Lei wrote: > > On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > >> On 1/18/18 11:47 AM, Bart Van Assche wrote: > This is all very tiresome. > >>> > >>> Yes, this is tiresome. It is very

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 10:32 +0800, Ming Lei wrote: > Now most of times both NVMe and SCSI won't return BLK_STS_RESOURCE, and > it should be DM-only which returns STS_RESOURCE so often. That's wrong at least for SCSI. See also https://marc.info/?l=linux-block=151578329417076. Bart.

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Fri, 2018-01-19 at 10:32 +0800, Ming Lei wrote: > Now most of times both NVMe and SCSI won't return BLK_STS_RESOURCE, and > it should be DM-only which returns STS_RESOURCE so often. That's wrong at least for SCSI. See also https://marc.info/?l=linux-block=151578329417076. Bart.

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/18/18 7:32 PM, Ming Lei wrote: > On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: >> On 1/18/18 11:47 AM, Bart Van Assche wrote: This is all very tiresome. >>> >>> Yes, this is tiresome. It is very annoying to me that others keep >>> introducing so many regressions in such

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/18/18 7:32 PM, Ming Lei wrote: > On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: >> On 1/18/18 11:47 AM, Bart Van Assche wrote: This is all very tiresome. >>> >>> Yes, this is tiresome. It is very annoying to me that others keep >>> introducing so many regressions in such

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > On 1/18/18 11:47 AM, Bart Van Assche wrote: > >> This is all very tiresome. > > > > Yes, this is tiresome. It is very annoying to me that others keep > > introducing so many regressions in such important parts of the kernel. > > It is

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18, 2018 at 01:11:01PM -0700, Jens Axboe wrote: > On 1/18/18 11:47 AM, Bart Van Assche wrote: > >> This is all very tiresome. > > > > Yes, this is tiresome. It is very annoying to me that others keep > > introducing so many regressions in such important parts of the kernel. > > It is

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 15:39 -0700, Jens Axboe wrote: > When you do have a solid test case, please please submit a blktests > test case for it! This needs to be something we can regularly in > testing. Hello Jens, That sounds like a good idea to me. BTW, I think the reason why so far I can

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 15:39 -0700, Jens Axboe wrote: > When you do have a solid test case, please please submit a blktests > test case for it! This needs to be something we can regularly in > testing. Hello Jens, That sounds like a good idea to me. BTW, I think the reason why so far I can

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/18/18 3:35 PM, Laurence Oberman wrote: > On Thu, 2018-01-18 at 22:24 +, Bart Van Assche wrote: >> On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: >>> OK, I ran 5 at once of 5 separate mount points. >>> I am using 4k block sizes >>> Its solid consistent for me. No stalls no

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On 1/18/18 3:35 PM, Laurence Oberman wrote: > On Thu, 2018-01-18 at 22:24 +, Bart Van Assche wrote: >> On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: >>> OK, I ran 5 at once of 5 separate mount points. >>> I am using 4k block sizes >>> Its solid consistent for me. No stalls no

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 22:24 +, Bart Van Assche wrote: > On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: > > OK, I ran 5 at once of 5 separate mount points. > > I am using 4k block sizes > > Its solid consistent for me. No stalls no gaps. > > Hi Laurence, > > That's great news and

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 22:24 +, Bart Van Assche wrote: > On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: > > OK, I ran 5 at once of 5 separate mount points. > > I am using 4k block sizes > > Its solid consistent for me. No stalls no gaps. > > Hi Laurence, > > That's great news and

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: > OK, I ran 5 at once of 5 separate mount points. > I am using 4k block sizes > Its solid consistent for me. No stalls no gaps. Hi Laurence, That's great news and thank you for having shared this information but I think it should be

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:18 -0500, Laurence Oberman wrote: > OK, I ran 5 at once of 5 separate mount points. > I am using 4k block sizes > Its solid consistent for me. No stalls no gaps. Hi Laurence, That's great news and thank you for having shared this information but I think it should be

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > And yet Laurence cannot reproduce any such lockups with your test... Hmm ... maybe I misunderstood Laurence but I don't think that Laurence has already succeeded at running an unmodified version of my tests. In one of the e-mails Laurence

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > And yet Laurence cannot reproduce any such lockups with your test... Hmm ... maybe I misunderstood Laurence but I don't think that Laurence has already succeeded at running an unmodified version of my tests. In one of the e-mails Laurence

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at  4:39pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > > > On Thu, Jan 18 2018 at  3:58P -0500, > > > Bart Van Assche

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 17:01 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at  4:39pm -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > > > On Thu, Jan 18 2018 at  3:58P -0500, > > > Bart Van Assche wrote: > > > > > > > On Thu, 2018-01-18 at 15:48

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18 2018 at 4:39pm -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > > On Thu, Jan 18 2018 at 3:58P -0500, > > Bart Van Assche wrote: > > > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18 2018 at 4:39pm -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > > On Thu, Jan 18 2018 at 3:58P -0500, > > Bart Van Assche wrote: > > > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > > > For Bart's test the underlying

Re: [dm-devel] [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 3:58P -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > > For Bart's test the underlying scsi-mq driver is what is regularly > > > hitting this

Re: [dm-devel] [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at 3:58P -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > > For Bart's test the underlying scsi-mq driver is what is regularly > > > hitting this case in

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at  3:58P -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > > For Bart's test the underlying scsi-mq driver is what is > > > regularly > > > hitting

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 16:23 -0500, Mike Snitzer wrote: > On Thu, Jan 18 2018 at  3:58P -0500, > Bart Van Assche wrote: > > > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > > For Bart's test the underlying scsi-mq driver is what is > > > regularly > > > hitting this case in

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18 2018 at 3:58P -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > For Bart's test the underlying scsi-mq driver is what is regularly > > hitting this case in __blk_mq_try_issue_directly(): > > > > if

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, Jan 18 2018 at 3:58P -0500, Bart Van Assche wrote: > On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > > For Bart's test the underlying scsi-mq driver is what is regularly > > hitting this case in __blk_mq_try_issue_directly(): > > > > if (blk_mq_hctx_stopped(hctx) ||

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > For Bart's test the underlying scsi-mq driver is what is regularly > hitting this case in __blk_mq_try_issue_directly(): > > if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) Hello Mike, That code path is not the code path

Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle

On Thu, 2018-01-18 at 15:48 -0500, Mike Snitzer wrote: > For Bart's test the underlying scsi-mq driver is what is regularly > hitting this case in __blk_mq_try_issue_directly(): > > if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) Hello Mike, That code path is not the code path

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