similar to: [PATCH for-2.6.35] virtio_net: do not reschedule rx refill forever

On Fri, Jun 04, 2010 at 10:28:56AM +0930, Rusty Russell wrote: > This patch is a subset of an already upstream patch, but this portion > is useful in earlier releases. > > Please consider for the 2.6.32 and 2.6.33 stable trees. > > If the add_buf operation fails, indicate failure to the caller. > > Signed-off-by: Bruce Rogers <brogers at novell.com> >

On Fri, Jun 04, 2010 at 10:28:56AM +0930, Rusty Russell wrote: > This patch is a subset of an already upstream patch, but this portion > is useful in earlier releases. > > Please consider for the 2.6.32 and 2.6.33 stable trees. > > If the add_buf operation fails, indicate failure to the caller. > > Signed-off-by: Bruce Rogers <brogers at novell.com> >

To even the latency, refill buffer right after being used. Sign-off-by: Shirley Ma <xma at us.ibm.com> --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 0c7321c..c8201d4 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -429,6 +429,22 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) return err; } +static bool

To even the latency, refill buffer right after being used. Sign-off-by: Shirley Ma <xma at us.ibm.com> --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 0c7321c..c8201d4 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -429,6 +429,22 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) return err; } +static bool

virtio net will never try to overflow the TX ring, so the only reason add_buf may fail is out of memory. Thus, we can not stop the device until some request completes - there's no guarantee anything at all is outstanding. Make the error message clearer as well: error here does not indicate queue full. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c |

virtio net will never try to overflow the TX ring, so the only reason add_buf may fail is out of memory. Thus, we can not stop the device until some request completes - there's no guarantee anything at all is outstanding. Make the error message clearer as well: error here does not indicate queue full. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c |

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/net/virtio_net.c

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/net/virtio_net.c

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+),

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/net/virtio_net.c

Too many places poke at [rs]q->vq->vdev->priv just to get the the vi structure. Let's just pass the pointer around: seems cleaner, and might even be faster. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/net/virtio_net.c

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can reschedule itself, if this happens it can run after cancel_delayed_work_sync, and will access device after it is destroyed. As a solution, add flags to track napi state and to disable refill, and toggle them on start, stop and remove; check these flags

Fix theoretical races related to refill work: 1. After napi is disabled by ndo_stop, refill work can run and re-enable it. 2. Refill can reschedule itself, if this happens it can run after cancel_delayed_work_sync, and will access device after it is destroyed. As a solution, add flags to track napi state and to disable refill, and toggle them on start, stop and remove; check these flags