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From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, Keith Busch <keith.busch@intel.com>,
	linux-nvme@lists.infradead.org
Subject: [PATCH 01/11] nvme: don't disable local ints for polled queue
Date: Tue, 13 Nov 2018 08:42:23 -0700	[thread overview]
Message-ID: <20181113154233.15256-2-axboe@kernel.dk> (raw)
In-Reply-To: <20181113154233.15256-1-axboe@kernel.dk>

A polled queued doesn't trigger interrupts, so it's always safe
to grab the queue lock without disabling interrupts.

Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-nvme@lists.infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/nvme/host/pci.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 6aa86dfcb32c..bb22ae567208 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1067,9 +1067,18 @@ static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
 	if (!nvme_cqe_pending(nvmeq))
 		return 0;
 
-	spin_lock_irq(&nvmeq->cq_lock);
+	/*
+	 * Polled queue doesn't have an IRQ, no need to disable ints
+	 */
+	if (!nvmeq->polled)
+		local_irq_disable();
+
+	spin_lock(&nvmeq->cq_lock);
 	found = nvme_process_cq(nvmeq, &start, &end, tag);
-	spin_unlock_irq(&nvmeq->cq_lock);
+	spin_unlock(&nvmeq->cq_lock);
+
+	if (!nvmeq->polled)
+		local_irq_enable();
 
 	nvme_complete_cqes(nvmeq, start, end);
 	return found;
-- 
2.17.1


  reply	other threads:[~2018-11-13 15:42 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-13 15:42 [PATCHSET v2 0/11] Various block optimizations Jens Axboe
2018-11-13 15:42 ` Jens Axboe [this message]
2018-11-13 15:42 ` [PATCH 02/11] block: add queue_is_mq() helper Jens Axboe
2018-11-14 15:23   ` Christoph Hellwig
2018-11-13 15:42 ` [PATCH 03/11] blk-mq: embed blk_mq_ops directly in the request queue Jens Axboe
2018-11-13 15:42 ` [PATCH 04/11] blk-rq-qos: inline check for q->rq_qos functions Jens Axboe
2018-11-13 15:42 ` [PATCH 05/11] block: avoid ordered task state change for polled IO Jens Axboe
2018-11-14  2:29   ` jianchao.wang
2018-11-14  2:35     ` Jens Axboe
2018-11-13 15:42 ` [PATCH 06/11] block: add polled wakeup task helper Jens Axboe
2018-11-13 15:52   ` Keith Busch
2018-11-13 15:58     ` Jens Axboe
2018-11-13 16:59       ` Jens Axboe
2018-11-13 15:42 ` [PATCH 07/11] block: have ->poll_fn() return number of entries polled Jens Axboe
2018-11-13 15:42 ` [PATCH 08/11] blk-mq: when polling for IO, look for any completion Jens Axboe
2018-11-13 15:42 ` [PATCH 09/11] block: make blk_poll() take a parameter on whether to spin or not Jens Axboe
2018-11-13 15:42 ` [PATCH 10/11] block: for async O_DIRECT, mark us as polling if asked to Jens Axboe
2018-11-13 15:42 ` [PATCH 11/11] block: don't plug for aio/O_DIRECT HIPRI IO Jens Axboe

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