From mboxrd@z Thu Jan 1 00:00:00 1970 From: keith.busch@intel.com (Keith Busch) Date: Tue, 4 Nov 2014 14:55:00 +0000 (UTC) Subject: [PATCH] NVMe: Re-attach waitqueue following device reset In-Reply-To: <5453DE85.90407@micron.com> References: <5453DE85.90407@micron.com> Message-ID: On Fri, 31 Oct 2014, Sam Bradshaw wrote: > Bios queued to sq_cong prior to and during a device reset may not > get re-issued or may get issued very slowly following the completion > of the reset sequence. The waitqueue was detached as part of the > sequence and never re-attached, forcing all new make_request() bios > to be queued and the queue to be flushed out without the help of the > completion path waking the kthread. Hi Sam, Are you using the latest from linux-nvme tree? I could have sworn this bug was fixed in commit: http://git.infradead.org/users/willy/linux-nvme.git/commitdiff/3559b4d2159aaae42f0fc0fa22e40312c45d4606 Please let me know if there's still a gap. > This patch re-attaches the waitqueue as part of the reset process. > > Signed-off-by: Sam Bradshaw > --- > diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c > index b85a2a0..8133ee8 100644 > --- a/drivers/block/nvme-core.c > +++ b/drivers/block/nvme-core.c > @@ -2329,6 +2329,23 @@ static int nvme_setup_io_queues(struct nvme_dev *dev) > nvme_free_queues(dev, nr_io_queues + 1); > nvme_assign_io_queues(dev); > > + /* Re-attach the waitqueue */ > + for (i = dev->queue_count - 1; i >= 1; i--) { > + struct nvme_queue *nvmeq = raw_nvmeq(dev, i); > + > + if (nvmeq) { > + spin_lock_irq(&nvmeq->q_lock); > + init_waitqueue_head(&nvmeq->sq_full); > + init_waitqueue_entry(&nvmeq->sq_cong_wait, > + nvme_thread); > + if (bio_list_peek(&nvmeq->sq_cong) || > + !list_empty(&nvmeq->iod_bio)) > + add_wait_queue(&nvmeq->sq_full, > + &nvmeq->sq_cong_wait); > + spin_unlock_irq(&nvmeq->q_lock); > + } > + } > + > return 0; > > free_queues: