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authorJason Wang <jasowang@redhat.com>2020-05-29 16:02:58 +0800
committerMichael S. Tsirkin <mst@redhat.com>2020-06-04 15:36:51 -0400
commit01fcb1cbc88effb3493c6197efc96b69b9f4823a (patch)
tree0334230859b145fbf8f10fe56ff06d3e5b17713f /drivers/vhost/scsi.c
parent5c1bd89b45d4c82316833a8d7ed36720ab89ee3d (diff)
vhost: allow device that does not depend on vhost worker
vDPA device currently relays the eventfd via vhost worker. This is inefficient due the latency of wakeup and scheduling, so this patch tries to introduce a use_worker attribute for the vhost device. When use_worker is not set with vhost_dev_init(), vhost won't try to allocate a worker thread and the vhost_poll will be processed directly in the wakeup function. This help for vDPA since it reduces the latency caused by vhost worker. In my testing, it saves 0.2 ms in pings between VMs on a mutual host. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200529080303.15449-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost/scsi.c')
-rw-r--r--drivers/vhost/scsi.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index c39952243fd3..0cbaa0b3893d 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1628,7 +1628,7 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
}
vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
- VHOST_SCSI_WEIGHT, 0, NULL);
+ VHOST_SCSI_WEIGHT, 0, true, NULL);
vhost_scsi_init_inflight(vs, NULL);