diff mbox series

[v6,5/9] virtio: blk/scsi: use block layer helpers to calculate num of queues

Message ID 20250424-isolcpus-io-queues-v6-5-9a53a870ca1f@kernel.org
State New
Headers show
Series blk: honor isolcpus configuration | expand

Commit Message

Daniel Wagner April 24, 2025, 6:19 p.m. UTC 
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.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
---
 drivers/block/virtio_blk.c | 5 ++---
 drivers/scsi/virtio_scsi.c | 1 +
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Ming Lei May 9, 2025, 1:52 a.m. UTC | #1 
On Thu, Apr 24, 2025 at 08:19:44PM +0200, Daniel Wagner wrote:
> 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.

With commit log fixed:

Reviewed-by: Ming Lei <ming.lei@redhat.com>

thanks,
Ming
diff mbox series

Patch

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 7cffea01d868c6dcfe6734d3c89c1709fec07956..975036e8ddef5d622bab623843826ac26a0aa63d 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -976,9 +976,8 @@  static int init_vq(struct virtio_blk *vblk)
 		return -EINVAL;
 	}
 
-	num_vqs = min_t(unsigned int,
-			min_not_zero(num_request_queues, nr_cpu_ids),
-			num_vqs);
+	num_vqs = blk_mq_num_possible_queues(
+			min_not_zero(num_request_queues, num_vqs));
 
 	num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
 
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 21ce3e9401929cd273fde08b0944e8b47e1e66cc..96a69edddbe5555574fc8fed1ba7c82a99df4472 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -919,6 +919,7 @@  static int virtscsi_probe(struct virtio_device *vdev)
 	/* We need to know how many queues before we allocate. */
 	num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
 	num_queues = min_t(unsigned int, nr_cpu_ids, num_queues);
+	num_queues = blk_mq_num_possible_queues(num_queues);
 
 	num_targets = virtscsi_config_get(vdev, max_target) + 1;