From: Ming Lei <ming.lei@redhat.com> To: "jianchao.wang" <jianchao.w.wang@oracle.com> Cc: Keith Busch <keith.busch@intel.com>, Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org, Sagi Grimberg <sagi@grimberg.me>, linux-nvme@lists.infradead.org, Christoph Hellwig <hch@lst.de> Subject: Re: [PATCH 1/2] nvme: pci: simplify timeout handling Date: Thu, 26 Apr 2018 23:57:24 +0800 [thread overview] Message-ID: <20180426155722.GA3597@ming.t460p> (raw) In-Reply-To: <b8dd2c24-a011-7e66-feca-502b0a6b10c0@oracle.com> Hi Jianchao, On Thu, Apr 26, 2018 at 11:07:56PM +0800, jianchao.wang wrote: > Hi Ming > > Thanks for your wonderful solution. :) > > On 04/26/2018 08:39 PM, Ming Lei wrote: > > +/* > > + * This one is called after queues are quiesced, and no in-fligh timeout > > + * and nvme interrupt handling. > > + */ > > +static void nvme_pci_cancel_request(struct request *req, void *data, > > + bool reserved) > > +{ > > + /* make sure timed-out requests are covered too */ > > + if (req->rq_flags & RQF_MQ_TIMEOUT_EXPIRED) { > > + req->aborted_gstate = 0; > > + req->rq_flags &= ~RQF_MQ_TIMEOUT_EXPIRED; > > + } > > + > > + nvme_cancel_request(req, data, reserved); > > +} > > + > > static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown) > > { > > int i; > > @@ -2223,10 +2316,17 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown) > > for (i = dev->ctrl.queue_count - 1; i >= 0; i--) > > nvme_suspend_queue(&dev->queues[i]); > > > > + /* > > + * safe to sync timeout after queues are quiesced, then all > > + * requests(include the time-out ones) will be canceled. > > + */ > > + nvme_sync_queues(&dev->ctrl); > > + blk_sync_queue(dev->ctrl.admin_q); > > + > Looks like blk_sync_queue cannot drain all the timeout work. > > blk_sync_queue > -> del_timer_sync > blk_mq_timeout_work > -> mod_timer > -> cancel_work_sync > the timeout work may come back again. > we may need to force all the in-flight requests to be timed out with blk_abort_request > blk_abort_request() seems over-kill, we could avoid this race simply by returning EH_NOT_HANDLED if the controller is in-recovery. > > nvme_pci_disable(dev); > > the interrupt will not come, but there maybe running one. > a synchronize_sched() here ? We may cover this case by moving nvme_suspend_queue() before nvme_stop_queues(). Both two are very good catch, thanks! -- Ming
WARNING: multiple messages have this Message-ID (diff)
From: ming.lei@redhat.com (Ming Lei) Subject: [PATCH 1/2] nvme: pci: simplify timeout handling Date: Thu, 26 Apr 2018 23:57:24 +0800 [thread overview] Message-ID: <20180426155722.GA3597@ming.t460p> (raw) In-Reply-To: <b8dd2c24-a011-7e66-feca-502b0a6b10c0@oracle.com> Hi Jianchao, On Thu, Apr 26, 2018@11:07:56PM +0800, jianchao.wang wrote: > Hi Ming > > Thanks for your wonderful solution. :) > > On 04/26/2018 08:39 PM, Ming Lei wrote: > > +/* > > + * This one is called after queues are quiesced, and no in-fligh timeout > > + * and nvme interrupt handling. > > + */ > > +static void nvme_pci_cancel_request(struct request *req, void *data, > > + bool reserved) > > +{ > > + /* make sure timed-out requests are covered too */ > > + if (req->rq_flags & RQF_MQ_TIMEOUT_EXPIRED) { > > + req->aborted_gstate = 0; > > + req->rq_flags &= ~RQF_MQ_TIMEOUT_EXPIRED; > > + } > > + > > + nvme_cancel_request(req, data, reserved); > > +} > > + > > static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown) > > { > > int i; > > @@ -2223,10 +2316,17 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown) > > for (i = dev->ctrl.queue_count - 1; i >= 0; i--) > > nvme_suspend_queue(&dev->queues[i]); > > > > + /* > > + * safe to sync timeout after queues are quiesced, then all > > + * requests(include the time-out ones) will be canceled. > > + */ > > + nvme_sync_queues(&dev->ctrl); > > + blk_sync_queue(dev->ctrl.admin_q); > > + > Looks like blk_sync_queue cannot drain all the timeout work. > > blk_sync_queue > -> del_timer_sync > blk_mq_timeout_work > -> mod_timer > -> cancel_work_sync > the timeout work may come back again. > we may need to force all the in-flight requests to be timed out with blk_abort_request > blk_abort_request() seems over-kill, we could avoid this race simply by returning EH_NOT_HANDLED if the controller is in-recovery. > > nvme_pci_disable(dev); > > the interrupt will not come, but there maybe running one. > a synchronize_sched() here ? We may cover this case by moving nvme_suspend_queue() before nvme_stop_queues(). Both two are very good catch, thanks! -- Ming
next prev parent reply other threads:[~2018-04-26 15:57 UTC|newest] Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-04-26 12:39 [PATCH 0/2] nvme: pci: fix & improve timeout handling Ming Lei 2018-04-26 12:39 ` Ming Lei 2018-04-26 12:39 ` [PATCH 1/2] nvme: pci: simplify " Ming Lei 2018-04-26 12:39 ` Ming Lei 2018-04-26 15:07 ` jianchao.wang 2018-04-26 15:07 ` jianchao.wang 2018-04-26 15:57 ` Ming Lei [this message] 2018-04-26 15:57 ` Ming Lei 2018-04-26 16:16 ` Ming Lei 2018-04-26 16:16 ` Ming Lei 2018-04-27 1:37 ` jianchao.wang 2018-04-27 1:37 ` jianchao.wang 2018-04-27 14:57 ` Ming Lei 2018-04-27 14:57 ` Ming Lei 2018-04-28 14:00 ` jianchao.wang 2018-04-28 14:00 ` jianchao.wang 2018-04-28 21:57 ` Ming Lei 2018-04-28 21:57 ` Ming Lei 2018-04-28 22:27 ` Ming Lei 2018-04-28 22:27 ` Ming Lei 2018-04-29 1:36 ` Ming Lei 2018-04-29 1:36 ` Ming Lei 2018-04-29 2:21 ` jianchao.wang 2018-04-29 2:21 ` jianchao.wang 2018-04-29 14:13 ` Ming Lei 2018-04-29 14:13 ` Ming Lei 2018-04-27 17:51 ` Keith Busch 2018-04-27 17:51 ` Keith Busch 2018-04-28 3:50 ` Ming Lei 2018-04-28 3:50 ` Ming Lei 2018-04-28 13:35 ` Keith Busch 2018-04-28 13:35 ` Keith Busch 2018-04-28 14:31 ` jianchao.wang 2018-04-28 14:31 ` jianchao.wang 2018-04-28 21:39 ` Ming Lei 2018-04-28 21:39 ` Ming Lei 2018-04-30 19:52 ` Keith Busch 2018-04-30 19:52 ` Keith Busch 2018-04-30 23:14 ` Ming Lei 2018-04-30 23:14 ` Ming Lei 2018-05-08 15:30 ` Keith Busch 2018-05-08 15:30 ` Keith Busch 2018-05-10 20:52 ` Ming Lei 2018-05-10 20:52 ` Ming Lei 2018-05-10 21:05 ` Keith Busch 2018-05-10 21:05 ` Keith Busch 2018-05-10 21:10 ` Ming Lei 2018-05-10 21:10 ` Ming Lei 2018-05-10 21:18 ` Keith Busch 2018-05-10 21:18 ` Keith Busch 2018-05-10 21:24 ` Ming Lei 2018-05-10 21:24 ` Ming Lei 2018-05-10 21:44 ` Keith Busch 2018-05-10 21:44 ` Keith Busch 2018-05-10 21:50 ` Ming Lei 2018-05-10 21:50 ` Ming Lei 2018-05-10 21:53 ` Ming Lei 2018-05-10 21:53 ` Ming Lei 2018-05-10 22:03 ` Ming Lei 2018-05-10 22:03 ` Ming Lei 2018-05-10 22:43 ` Keith Busch 2018-05-10 22:43 ` Keith Busch 2018-05-11 0:14 ` Ming Lei 2018-05-11 0:14 ` Ming Lei 2018-05-11 2:10 ` Ming Lei 2018-05-11 2:10 ` Ming Lei 2018-04-26 12:39 ` [PATCH 2/2] nvme: pci: guarantee EH can make progress Ming Lei 2018-04-26 12:39 ` Ming Lei 2018-04-26 16:24 ` Keith Busch 2018-04-26 16:24 ` Keith Busch 2018-04-28 3:28 ` Ming Lei 2018-04-28 3:28 ` Ming Lei
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