From 0a50ed0574ffe853f15c3430794b5439b2e6150a Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Tue, 17 Jun 2025 15:43:27 +0200 Subject: [PATCH] virtio: blk/scsi: use block layer helpers to calculate num of queues The calculation of the upper limit for queues does not depend solely on the number of possible CPUs; for example, the isolcpus kernel command-line option must also be considered. To account for this, the block layer provides a helper function to retrieve the maximum number of queues. Use it to set an appropriate upper queue number limit. Reviewed-by: Christoph Hellwig Acked-by: Michael S. Tsirkin Reviewed-by: Hannes Reinecke Reviewed-by: Ming Lei Signed-off-by: Daniel Wagner Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20250617-isolcpus-queue-counters-v1-5-13923686b54b@kernel.org Signed-off-by: Jens Axboe --- drivers/block/virtio_blk.c | 5 ++--- drivers/scsi/virtio_scsi.c | 1 + 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 30bca8cb71060..e649fa67bac16 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 21ce3e9401929..96a69edddbe55 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; -- 2.47.2