similar to: [PATCH v2] vhost: replace % with & on data path

On Wed, Mar 19, 2014 at 10:48 AM, Venkatesh Srinivas <venkateshs at google.com> wrote: >> And I rewrote it substantially, mainly to take >> VIRTIO_RING_F_INDIRECT_DESC into account. >> >> As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't >> have made a change. This version does (since QEMU also offers >>

On Wed, Mar 19, 2014 at 10:48 AM, Venkatesh Srinivas <venkateshs at google.com> wrote: >> And I rewrote it substantially, mainly to take >> VIRTIO_RING_F_INDIRECT_DESC into account. >> >> As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't >> have made a change. This version does (since QEMU also offers >>

tytso at mit.edu writes: > On Mon, Mar 17, 2014 at 11:12:15AM +1030, Rusty Russell wrote: >> >> Note that with indirect descriptors (which is supported by Almost >> Everyone), we can actually use the full index, so this value is a bit >> pessimistic. But it's OK as a starting point. > > So is this something that can go upstream with perhaps a slight >

tytso at mit.edu writes: > On Mon, Mar 17, 2014 at 11:12:15AM +1030, Rusty Russell wrote: >> >> Note that with indirect descriptors (which is supported by Almost >> Everyone), we can actually use the full index, so this value is a bit >> pessimistic. But it's OK as a starting point. > > So is this something that can go upstream with perhaps a slight >

virtio-blk set the default queue depth to 64 requests, which was insufficient for high-IOPS devices. Instead set the blk-queue depth to the device's virtqueue depth divided by two (each I/O requires at least two VQ entries). Signed-off-by: Venkatesh Srinivas <venkateshs at google.com> --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git

virtio-blk set the default queue depth to 64 requests, which was insufficient for high-IOPS devices. Instead set the blk-queue depth to the device's virtqueue depth divided by two (each I/O requires at least two VQ entries). Signed-off-by: Venkatesh Srinivas <venkateshs at google.com> --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git

On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: > On Tue, Nov 10, 2015 at 04:21:07PM -0800, Venkatesh Srinivas wrote: > > Improves cacheline transfer flow of available ring header. > > > > Virtqueues are implemented as a pair of rings, one producer->consumer > > avail ring and one consumer->producer used ring; preceding the > > avail ring

On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: > On Tue, Nov 10, 2015 at 04:21:07PM -0800, Venkatesh Srinivas wrote: > > Improves cacheline transfer flow of available ring header. > > > > Virtqueues are implemented as a pair of rings, one producer->consumer > > avail ring and one consumer->producer used ring; preceding the > > avail ring

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fb0eae4..49d84e5 100644 --- a/drivers/net/virtio_net.c +++

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fb0eae4..49d84e5 100644 --- a/drivers/net/virtio_net.c +++

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> -- v2: replace also netdev_alloc_skb_ip_align() invocation in add_recvbuf_small(), suggested by Venkatesh Srinivas --- drivers/net/virtio_net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git

This gives small but noticeable rx performance improvement (2-3%) and will allow exploiting future napi improvement. Signed-off-by: Paolo Abeni <pabeni at redhat.com> -- v2: replace also netdev_alloc_skb_ip_align() invocation in add_recvbuf_small(), suggested by Venkatesh Srinivas --- drivers/net/virtio_net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git

On 11/18/2015 12:28 PM, Venkatesh Srinivas wrote: > On Tue, Nov 17, 2015 at 08:08:18PM -0800, Venkatesh Srinivas wrote: >> On Mon, Nov 16, 2015 at 7:46 PM, Xie, Huawei <huawei.xie at intel.com> wrote: >> >>> On 11/14/2015 7:41 AM, Venkatesh Srinivas wrote: >>>> On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: >>>>> On Tue,

Improves cacheline transfer flow of available ring header. Virtqueues are implemented as a pair of rings, one producer->consumer avail ring and one consumer->producer used ring; preceding the avail ring in memory are two contiguous u16 fields -- avail->flags and avail->idx. A producer posts work by writing to avail->idx and a consumer reads avail->idx. The flags and idx fields

Improves cacheline transfer flow of available ring header. Virtqueues are implemented as a pair of rings, one producer->consumer avail ring and one consumer->producer used ring; preceding the avail ring in memory are two contiguous u16 fields -- avail->flags and avail->idx. A producer posts work by writing to avail->idx and a consumer reads avail->idx. The flags and idx fields

Venkatesh Srinivas <venkateshs at google.com> writes: > On Wed, Mar 19, 2014 at 10:48 AM, Venkatesh Srinivas > <venkateshs at google.com> wrote: >>> And I rewrote it substantially, mainly to take >>> VIRTIO_RING_F_INDIRECT_DESC into account. >>> >>> As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't >>> have

On Mon, Nov 16, 2015 at 7:46 PM, Xie, Huawei <huawei.xie at intel.com> wrote: > On 11/14/2015 7:41 AM, Venkatesh Srinivas wrote: > > On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: > >> On Tue, Nov 10, 2015 at 04:21:07PM -0800, Venkatesh Srinivas wrote: > >>> Improves cacheline transfer flow of available ring header. > >>> >

On Mon, Nov 16, 2015 at 7:46 PM, Xie, Huawei <huawei.xie at intel.com> wrote: > On 11/14/2015 7:41 AM, Venkatesh Srinivas wrote: > > On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: > >> On Tue, Nov 10, 2015 at 04:21:07PM -0800, Venkatesh Srinivas wrote: > >>> Improves cacheline transfer flow of available ring header. > >>> >

On 11/14/2015 7:41 AM, Venkatesh Srinivas wrote: > On Wed, Nov 11, 2015 at 02:34:33PM +0200, Michael S. Tsirkin wrote: >> On Tue, Nov 10, 2015 at 04:21:07PM -0800, Venkatesh Srinivas wrote: >>> Improves cacheline transfer flow of available ring header. >>> >>> Virtqueues are implemented as a pair of rings, one producer->consumer >>> avail ring and

On Thu, Mar 17, 2016 at 7:44 AM, Paolo Abeni <pabeni at redhat.com> wrote: > > This gives small but noticeable rx performance improvement (2-3%) > and will allow exploiting future napi improvement. > > Signed-off-by: Paolo Abeni <pabeni at redhat.com> > --- Worked in my tests, though the performance win was in the noise (+0.6% - +1% bandwidth). What tests did you see