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[PATCH 10/10] vhost-scsi: create a woker per IO vq
From: |
Mike Christie |
Subject: |
[PATCH 10/10] vhost-scsi: create a woker per IO vq |
Date: |
Thu, 12 Nov 2020 17:19:10 -0600 |
This patch has vhost-scsi create a worker thread per IO vq.
It also adds a modparam to enable the feature, because I was thinking
existing setups might not be expecting the extra threading use, so the
default is to use the old single thread multiple vq behavior.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
drivers/vhost/scsi.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 612359d..3fb147f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -62,6 +62,12 @@
*/
#define VHOST_SCSI_WEIGHT 256
+static bool vhost_scsi_worker_per_io_vq;
+module_param_named(thread_per_io_virtqueue, vhost_scsi_worker_per_io_vq, bool,
+ 0644);
+MODULE_PARM_DESC(thread_per_io_virtqueue,
+ "Create a worker thread per IO virtqueue. Set to true to turn
on. Default is false where all virtqueues share a thread.");
+
struct vhost_scsi_inflight {
/* Wait for the flush operation to finish */
struct completion comp;
@@ -1805,6 +1811,36 @@ static int vhost_scsi_set_features(struct vhost_scsi
*vs, u64 features)
return 0;
}
+static int vhost_scsi_enable_vring(struct vhost_virtqueue *vq, bool enable)
+{
+ struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
+ /*
+ * For compat, we have the evt, ctl and first IO vq share worker0 like
+ * is setup by default. Additional vqs get their own worker.
+ */
+ if (vq == &vs->vqs[VHOST_SCSI_VQ_CTL].vq ||
+ vq == &vs->vqs[VHOST_SCSI_VQ_EVT].vq ||
+ vq == &vs->vqs[VHOST_SCSI_VQ_IO].vq)
+ return 0;
+
+ if (enable) {
+ if (!vhost_scsi_worker_per_io_vq)
+ return 0;
+ if (vq->worker_id != 0)
+ return 0;
+ return vhost_vq_worker_add(vq->dev, vq);
+ } else {
+ if (vq->worker_id == 0)
+ return 0;
+ vhost_vq_worker_remove(vq->dev, vq);
+ return 0;
+ }
+}
+
+static struct vhost_dev_ops vhost_scsi_dev_ops = {
+ .enable_vring = vhost_scsi_enable_vring,
+};
+
static int vhost_scsi_open(struct inode *inode, struct file *f)
{
struct vhost_scsi_virtqueue *svq;
@@ -1843,7 +1879,7 @@ static int vhost_scsi_open(struct inode *inode, struct
file *f)
svq->vq.handle_kick = vhost_scsi_handle_kick;
}
vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
- VHOST_SCSI_WEIGHT, 0, true, NULL);
+ VHOST_SCSI_WEIGHT, 0, true, &vhost_scsi_dev_ops);
vhost_scsi_init_inflight(vs, NULL);
--
1.8.3.1
- Re: [PATCH 09/10] vhost: add VHOST_SET_VRING_ENABLE support, (continued)
- [PATCH 03/10] vhost poll: fix coding style, Mike Christie, 2020/11/12
- [PATCH 07/10] vhost, vhost-scsi: flush IO vqs then send TMF rsp, Mike Christie, 2020/11/12
- [PATCH 02/10] vhost scsi: remove extra flushes, Mike Christie, 2020/11/12
- [PATCH 01/10] vhost: remove work arg from vhost_work_flush, Mike Christie, 2020/11/12
- [PATCH 04/10] vhost: support multiple worker threads, Mike Christie, 2020/11/12
- [PATCH 10/10] vhost-scsi: create a woker per IO vq,
Mike Christie <=
- [PATCH 06/10] vhost scsi: make SCSI cmd completion per vq, Mike Christie, 2020/11/12
- [PATCH 1/1] qemu vhost scsi: add VHOST_SET_VRING_ENABLE support, Mike Christie, 2020/11/12
- Re: [PATCH 00/10] vhost/qemu: thread per IO SCSI vq, Stefan Hajnoczi, 2020/11/17