linux-kernel - [PATCH v3 11/15] nvme-pci: use block layer helpers to calculate num of queues

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240806-isolcpus-io-queues-v3-11-da0eecfeaf8b@suse.de>
Date: Tue, 06 Aug 2024 14:06:43 +0200
From: Daniel Wagner <dwagner@...e.de>
To: Jens Axboe <axboe@...nel.dk>, Keith Busch <kbusch@...nel.org>, 
 Sagi Grimberg <sagi@...mberg.me>, Thomas Gleixner <tglx@...utronix.de>, 
 Christoph Hellwig <hch@....de>, 
 "Martin K. Petersen" <martin.petersen@...cle.com>, 
 John Garry <john.g.garry@...cle.com>, "Michael S. Tsirkin" <mst@...hat.com>, 
 Jason Wang <jasowang@...hat.com>, 
 Kashyap Desai <kashyap.desai@...adcom.com>, 
 Sumit Saxena <sumit.saxena@...adcom.com>, 
 Shivasharan S <shivasharan.srikanteshwara@...adcom.com>, 
 Chandrakanth patil <chandrakanth.patil@...adcom.com>, 
 Sathya Prakash Veerichetty <sathya.prakash@...adcom.com>, 
 Suganath Prabu Subramani <suganath-prabu.subramani@...adcom.com>, 
 Nilesh Javali <njavali@...vell.com>, GR-QLogic-Storage-Upstream@...vell.com, 
 Jonathan Corbet <corbet@....net>
Cc: Frederic Weisbecker <frederic@...nel.org>, Mel Gorman <mgorman@...e.de>, 
 Hannes Reinecke <hare@...e.de>, 
 Sridhar Balaraman <sbalaraman@...allelwireless.com>, 
 "brookxu.cn" <brookxu.cn@...il.com>, Ming Lei <ming.lei@...hat.com>, 
 linux-kernel@...r.kernel.org, linux-block@...r.kernel.org, 
 linux-nvme@...ts.infradead.org, linux-scsi@...r.kernel.org, 
 virtualization@...ts.linux.dev, megaraidlinux.pdl@...adcom.com, 
 mpi3mr-linuxdrv.pdl@...adcom.com, MPT-FusionLinux.pdl@...adcom.com, 
 storagedev@...rochip.com, linux-doc@...r.kernel.org, 
 Daniel Wagner <dwagner@...e.de>
Subject: [PATCH v3 11/15] nvme-pci: use block layer helpers to calculate
 num of queues

Multiqueue devices should only allocate queues for the housekeeping CPUs
when isolcpus=io_queue is set. This avoids that the isolated CPUs get
disturbed with OS workload.

Use helpers which calculates the correct number of queues which should
be used when isolcpus is used.

Signed-off-by: Daniel Wagner <dwagner@...e.de>
---
 drivers/nvme/host/pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 5d509405a3e4..50ff2cef3d4f 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -81,7 +81,7 @@ static int io_queue_count_set(const char *val, const struct kernel_param *kp)
 	int ret;

 	ret = kstrtouint(val, 10, &n);
-	if (ret != 0 || n > num_possible_cpus())
+	if (ret != 0 || n > blk_mq_num_possible_queues(0))
 		return -EINVAL;
 	return param_set_uint(val, kp);
 }
@@ -2300,7 +2300,8 @@ static unsigned int nvme_max_io_queues(struct nvme_dev *dev)
 	 */
 	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
 		return 1;
-	return num_possible_cpus() + dev->nr_write_queues + dev->nr_poll_queues;
+	return blk_mq_num_possible_queues(0) + dev->nr_write_queues +
+		dev->nr_poll_queues;
 }

 static int nvme_setup_io_queues(struct nvme_dev *dev)

-- 
2.46.0