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author | Jason Wang <jasowang@redhat.com> | 2019-05-17 00:29:49 -0400 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2019-05-27 11:08:22 -0400 |
commit | e82b9b0727ff6d665fff2d326162b460dded554d (patch) | |
tree | c88a7558ef9b90b1de6415a9cf99bb0206b71fad /drivers/vhost/scsi.c | |
parent | 6166e5330c3828699859a6ec1af21eef7c58778c (diff) | |
download | linux-stable-e82b9b0727ff6d665fff2d326162b460dded554d.tar.gz linux-stable-e82b9b0727ff6d665fff2d326162b460dded554d.tar.bz2 linux-stable-e82b9b0727ff6d665fff2d326162b460dded554d.zip |
vhost: introduce vhost_exceeds_weight()
We used to have vhost_exceeds_weight() for vhost-net to:
- prevent vhost kthread from hogging the cpu
- balance the time spent between TX and RX
This function could be useful for vsock and scsi as well. So move it
to vhost.c. Device must specify a weight which counts the number of
requests, or it can also specific a byte_weight which counts the
number of bytes that has been processed.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost/scsi.c')
-rw-r--r-- | drivers/vhost/scsi.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index c090d177bd75..27c9dac9f518 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -57,6 +57,12 @@ #define VHOST_SCSI_PREALLOC_UPAGES 2048 #define VHOST_SCSI_PREALLOC_PROT_SGLS 2048 +/* Max number of requests before requeueing the job. + * Using this limit prevents one virtqueue from starving others with + * request. + */ +#define VHOST_SCSI_WEIGHT 256 + struct vhost_scsi_inflight { /* Wait for the flush operation to finish */ struct completion comp; @@ -1621,7 +1627,8 @@ static int vhost_scsi_open(struct inode *inode, struct file *f) vqs[i] = &vs->vqs[i].vq; vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick; } - vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV); + vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV, + VHOST_SCSI_WEIGHT, 0); vhost_scsi_init_inflight(vs, NULL); |