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| author | Jason Wang <jasowang@redhat.com> | 2020-05-29 16:02:58 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-06-04 15:36:51 -0400 |
| commit | 01fcb1cbc88effb3493c6197efc96b69b9f4823a (patch) | |
| tree | 0334230859b145fbf8f10fe56ff06d3e5b17713f /drivers/vhost/vhost.h | |
| parent | 5c1bd89b45d4c82316833a8d7ed36720ab89ee3d (diff) | |
| download | linux-01fcb1cbc88effb3493c6197efc96b69b9f4823a.tar.bz2 | |
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/vhost.h')
| -rw-r--r-- | drivers/vhost/vhost.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 60cab4c78229..c8e96a095d3b 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -154,6 +154,7 @@ struct vhost_dev { int weight; int byte_weight; u64 kcov_handle; + bool use_worker; int (*msg_handler)(struct vhost_dev *dev, struct vhost_iotlb_msg *msg); }; @@ -161,6 +162,7 @@ struct vhost_dev { bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs, int iov_limit, int weight, int byte_weight, + bool use_worker, int (*msg_handler)(struct vhost_dev *dev, struct vhost_iotlb_msg *msg)); long vhost_dev_set_owner(struct vhost_dev *dev); |