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From: Niklas Schnelle <schnelle@linux.ibm.com>
To: linux-nvme@lists.infradead.org
Cc: Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
	Sagi Grimberg <sagi@grimberg.me>,
	linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>
Subject: [PATCH 2/2] nvme-pci: don't allocate unused I/O queues
Date: Thu, 12 Nov 2020 09:23:02 +0100	[thread overview]
Message-ID: <20201112082302.82441-3-schnelle@linux.ibm.com> (raw)
In-Reply-To: <20201112082302.82441-1-schnelle@linux.ibm.com>

currently the NVME_QUIRK_SHARED_TAGS quirk for Apple devices is handled
during the assignment of nr_io_queues in nvme_setup_io_queues().
This however means that for these devices nvme_max_io_queues() will
actually not return the supported maximum which is confusing and
unexpected and also means that in nvme_probe() we are allocating
for I/O queues that will never be used.
Fix this by moving the quirk handling into nvme_max_io_queues().

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/nvme/host/pci.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index b56250b83bdf..0f8cea5b30eb 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2089,6 +2089,12 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)
 
 static unsigned int nvme_max_io_queues(struct nvme_dev *dev)
 {
+	/*
+	 * If tags are shared with admin queue (Apple bug), then
+	 * make sure we only use one IO queue.
+	 */
+	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
+		return 1;
 	return num_possible_cpus() + dev->nr_write_queues + dev->nr_poll_queues;
 }
 
@@ -2107,15 +2113,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	dev->nr_write_queues = write_queues;
 	dev->nr_poll_queues = poll_queues;
 
-	/*
-	 * If tags are shared with admin queue (Apple bug), then
-	 * make sure we only use one IO queue.
-	 */
-	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
-		nr_io_queues = 1;
-	else
-		nr_io_queues = dev->nr_allocated_queues - 1;
-
+	nr_io_queues = dev->nr_allocated_queues - 1;
 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
 	if (result < 0)
 		return result;
-- 
2.17.1


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Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

WARNING: multiple messages have this Message-ID (diff)
From: Niklas Schnelle <schnelle@linux.ibm.com>
To: linux-nvme@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>,
	Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>,
	Sagi Grimberg <sagi@grimberg.me>
Subject: [PATCH 2/2] nvme-pci: don't allocate unused I/O queues
Date: Thu, 12 Nov 2020 09:23:02 +0100	[thread overview]
Message-ID: <20201112082302.82441-3-schnelle@linux.ibm.com> (raw)
In-Reply-To: <20201112082302.82441-1-schnelle@linux.ibm.com>

currently the NVME_QUIRK_SHARED_TAGS quirk for Apple devices is handled
during the assignment of nr_io_queues in nvme_setup_io_queues().
This however means that for these devices nvme_max_io_queues() will
actually not return the supported maximum which is confusing and
unexpected and also means that in nvme_probe() we are allocating
for I/O queues that will never be used.
Fix this by moving the quirk handling into nvme_max_io_queues().

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/nvme/host/pci.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index b56250b83bdf..0f8cea5b30eb 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2089,6 +2089,12 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)
 
 static unsigned int nvme_max_io_queues(struct nvme_dev *dev)
 {
+	/*
+	 * If tags are shared with admin queue (Apple bug), then
+	 * make sure we only use one IO queue.
+	 */
+	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
+		return 1;
 	return num_possible_cpus() + dev->nr_write_queues + dev->nr_poll_queues;
 }
 
@@ -2107,15 +2113,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
 	dev->nr_write_queues = write_queues;
 	dev->nr_poll_queues = poll_queues;
 
-	/*
-	 * If tags are shared with admin queue (Apple bug), then
-	 * make sure we only use one IO queue.
-	 */
-	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
-		nr_io_queues = 1;
-	else
-		nr_io_queues = dev->nr_allocated_queues - 1;
-
+	nr_io_queues = dev->nr_allocated_queues - 1;
 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
 	if (result < 0)
 		return result;
-- 
2.17.1


  parent reply	other threads:[~2020-11-12  8:23 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-12  8:23 [PATCH 0/2] nvme-pic: improve max I/O queue handling Niklas Schnelle
2020-11-12  8:23 ` Niklas Schnelle
2020-11-12  8:23 ` [PATCH 1/2] nvme-pci: drop min() from nr_io_queues assignment Niklas Schnelle
2020-11-12  8:23   ` Niklas Schnelle
2020-11-14  9:06   ` Christoph Hellwig
2020-11-14  9:06     ` Christoph Hellwig
2020-11-12  8:23 ` Niklas Schnelle [this message]
2020-11-12  8:23   ` [PATCH 2/2] nvme-pci: don't allocate unused I/O queues Niklas Schnelle
2020-11-12 14:53 ` [PATCH 0/2] nvme-pic: improve max I/O queue handling Keith Busch
2020-11-12 14:53   ` Keith Busch
2020-11-12 15:45   ` Niklas Schnelle
2020-11-12 15:45     ` Niklas Schnelle
2020-11-12 17:36     ` Keith Busch
2020-11-12 17:36       ` Keith Busch
2020-11-13 13:15       ` Niklas Schnelle
2020-11-13 13:15         ` Niklas Schnelle
2020-11-13 16:25         ` Christoph Hellwig
2020-11-13 16:25           ` Christoph Hellwig
2020-11-13 16:52           ` Niklas Schnelle
2020-11-13 16:52             ` Niklas Schnelle

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