From: JeffleXu <jefflexu@linux.alibaba.com>
To: Jason Wang <jasowang@redhat.com>,
Joseph Qi <joseph.qi@linux.alibaba.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org
Subject: Re: [PATCH RFC] virtio-blk: support per-device queue depth
Date: Tue, 19 Jan 2021 09:33:41 +0800 [thread overview]
Message-ID: <4141645d-6dfc-110c-bfcd-03641df8332c@linux.alibaba.com> (raw)
In-Reply-To: <ab4cbc06-b629-dd35-52ac-1246d500d1c4@redhat.com>
On 1/18/21 1:25 PM, Jason Wang wrote:
>
> On 2021/1/18 上午11:58, Joseph Qi wrote:
>> module parameter 'virtblk_queue_depth' was firstly introduced for
>> testing/benchmarking purposes described in commit fc4324b4597c
>> ("virtio-blk: base queue-depth on virtqueue ringsize or module param").
>> Since we have different virtio-blk devices which have different
>> capabilities, it requires that we support per-device queue depth instead
>> of per-module. So defaultly use vq free elements if module parameter
>> 'virtblk_queue_depth' is not set.
>
>
> I wonder if it's better to use sysfs instead (or whether it has already
> had something like this in the blocker layer).
>
"/sys/block/<dev>/queue/nr_requests" indeed works, but isn't better to
set queue_depth according to the hardware capability at the very first?
AFAIK, nvme just set per-device queue_depth at initializing phase.
Thanks,
Jeffle
>
>
>>
>> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>> ---
>> drivers/block/virtio_blk.c | 12 +++++++-----
>> 1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
>> index 145606d..f83a417 100644
>> --- a/drivers/block/virtio_blk.c
>> +++ b/drivers/block/virtio_blk.c
>> @@ -705,6 +705,7 @@ static int virtblk_probe(struct virtio_device *vdev)
>> u32 v, blk_size, max_size, sg_elems, opt_io_size;
>> u16 min_io_size;
>> u8 physical_block_exp, alignment_offset;
>> + unsigned int queue_depth;
>> if (!vdev->config->get) {
>> dev_err(&vdev->dev, "%s failure: config access disabled\n",
>> @@ -755,17 +756,18 @@ static int virtblk_probe(struct virtio_device
>> *vdev)
>> goto out_free_vq;
>> }
>> - /* Default queue sizing is to fill the ring. */
>> - if (!virtblk_queue_depth) {
>> - virtblk_queue_depth = vblk->vqs[0].vq->num_free;
>> + if (likely(!virtblk_queue_depth)) {
>> + queue_depth = vblk->vqs[0].vq->num_free;
>> /* ... but without indirect descs, we use 2 descs per req */
>> if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
>> - virtblk_queue_depth /= 2;
>> + queue_depth /= 2;
>> + } else {
>> + queue_depth = virtblk_queue_depth;
>> }
>> memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
>> vblk->tag_set.ops = &virtio_mq_ops;
>> - vblk->tag_set.queue_depth = virtblk_queue_depth;
>> + vblk->tag_set.queue_depth = queue_depth;
>> vblk->tag_set.numa_node = NUMA_NO_NODE;
>> vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
>> vblk->tag_set.cmd_size =
--
Thanks,
Jeffle
next prev parent reply other threads:[~2021-01-19 1:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 3:58 [PATCH RFC] virtio-blk: support per-device queue depth Joseph Qi
2021-01-18 5:25 ` Jason Wang
2021-01-18 6:06 ` Joseph Qi
2021-01-19 4:04 ` Jason Wang
2021-01-19 1:33 ` JeffleXu [this message]
2021-01-19 4:06 ` Jason Wang
2021-01-20 1:51 ` JeffleXu
2021-01-20 2:47 ` Jason Wang
2021-01-19 4:14 ` Jason Wang
2021-01-22 1:43 ` Joseph Qi
2021-01-22 8:34 ` Michael S. Tsirkin
2021-01-22 9:13 ` Joseph Qi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4141645d-6dfc-110c-bfcd-03641df8332c@linux.alibaba.com \
--to=jefflexu@linux.alibaba.com \
--cc=jasowang@redhat.com \
--cc=joseph.qi@linux.alibaba.com \
--cc=linux-block@vger.kernel.org \
--cc=mst@redhat.com \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).