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| author | Max Gurtovoy <mgurtovoy@nvidia.com> | 2021-09-02 22:46:22 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2021-11-01 09:29:47 +0100 |
| commit | 0989c41bed96e5dcf7939c6303e3759f02c4c16f (patch) | |
| tree | c1e2b7077e17bbdbfd8ffd66bbaf7da608734f1e /drivers/block/virtio_blk.c | |
| parent | virtio-blk: avoid preallocating big SGL for data (diff) | |
| download | linux-0989c41bed96e5dcf7939c6303e3759f02c4c16f.tar.xz linux-0989c41bed96e5dcf7939c6303e3759f02c4c16f.zip | |
virtio-blk: add num_request_queues module parameter
Sometimes a user would like to control the amount of request queues to
be created for a block device. For example, for limiting the memory
footprint of virtio-blk devices.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Link: https://lore.kernel.org/r/20210902204622.54354-1-mgurtovoy@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/block/virtio_blk.c')
| -rw-r--r-- | drivers/block/virtio_blk.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6767fb709d25..a33fe0743672 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -30,6 +30,25 @@ #define VIRTIO_BLK_INLINE_SG_CNT 2 #endif +static int virtblk_queue_count_set(const char *val, + const struct kernel_param *kp) +{ + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); +} + +static const struct kernel_param_ops queue_count_ops = { + .set = virtblk_queue_count_set, + .get = param_get_uint, +}; + +static unsigned int num_request_queues; +module_param_cb(num_request_queues, &queue_count_ops, &num_request_queues, + 0644); +MODULE_PARM_DESC(num_request_queues, + "Limit the number of request queues to use for blk device. " + "0 for no limit. " + "Values > nr_cpu_ids truncated to nr_cpu_ids."); + static int major; static DEFINE_IDA(vd_index_ida); @@ -553,7 +572,9 @@ static int init_vq(struct virtio_blk *vblk) if (err) num_vqs = 1; - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); + num_vqs = min_t(unsigned int, + min_not_zero(num_request_queues, nr_cpu_ids), + num_vqs); vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); if (!vblk->vqs) |