similar to: [PULL net-2.6] vhost: cleanups and fixes

The following changes since commit a351e9b9fc24e982ec2f0e76379a49826036da12: Linux 4.11 (2017-04-30 19:47:48 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to c8b0d7290657996a29f318b948d2397d30e70c36: s390/virtio: change maintainership (2017-05-09 16:43:25 +0300)

The following changes since commit a351e9b9fc24e982ec2f0e76379a49826036da12: Linux 4.11 (2017-04-30 19:47:48 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to c8b0d7290657996a29f318b948d2397d30e70c36: s390/virtio: change maintainership (2017-05-09 16:43:25 +0300)

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

The virtio-net device currently uses aligned MTU-sized mergeable receive packet buffers. Network throughput for workloads with large average packet size can be improved by posting larger receive packet buffers. However, due to SKB truesize effects, posting large (e.g, PAGE_SIZE) buffers reduces the throughput of workloads that do not benefit from GRO and have no large inbound packets. This

The virtio-net device currently uses aligned MTU-sized mergeable receive packet buffers. Network throughput for workloads with large average packet size can be improved by posting larger receive packet buffers. However, due to SKB truesize effects, posting large (e.g, PAGE_SIZE) buffers reduces the throughput of workloads that do not benefit from GRO and have no large inbound packets. This

The virtio-net device currently uses aligned MTU-sized mergeable receive packet buffers. Network throughput for workloads with large average packet size can be improved by posting larger receive packet buffers. However, due to SKB truesize effects, posting large (e.g, PAGE_SIZE) buffers reduces the throughput of workloads that do not benefit from GRO and have no large inbound packets. This

The virtio-net device currently uses aligned MTU-sized mergeable receive packet buffers. Network throughput for workloads with large average packet size can be improved by posting larger receive packet buffers. However, due to SKB truesize effects, posting large (e.g, PAGE_SIZE) buffers reduces the throughput of workloads that do not benefit from GRO and have no large inbound packets. This

copy_from_user is pretty high on perf top profile, replacing it with __copy_from_user helps. It's also safe because we do access_ok checks during setup. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index ade0568..01701b8 100644 ---

copy_from_user is pretty high on perf top profile, replacing it with __copy_from_user helps. It's also safe because we do access_ok checks during setup. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index ade0568..01701b8 100644 ---

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

When ring size is small (<32 entries) making buffers smaller means a full ring might not be able to hold enough buffers to fit a single large packet. Make sure a ring full of buffers is large enough to allow at least one packet of max size. Fixes: 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") Signed-off-by: Michael S. Tsirkin <mst at

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag allocators") changed the mergeable receive buffer size from PAGE_SIZE to MTU-size. However, the merge buffer size does not take into account the size of the virtio-net header. Consequently, packets that are MTU-size will take two buffers intead of one (to store the virtio-net header), substantially decreasing the

----- ???? ----- > On Wed, Nov 20, 2013 at 05:07:25PM +0800, Jason Wang wrote: > > When mergeable buffer were used, we only put the first page buf leave the > > rest > > of buffers in the virt queue. This will cause the driver could not get the > > correct head buffer any more. Fix this by dropping the rest of buffers for > > this > > packet. > > >

----- ???? ----- > On Wed, Nov 20, 2013 at 05:07:25PM +0800, Jason Wang wrote: > > When mergeable buffer were used, we only put the first page buf leave the > > rest > > of buffers in the virt queue. This will cause the driver could not get the > > correct head buffer any more. Fix this by dropping the rest of buffers for > > this > > packet. > > >

Hi Joe, [auto build test WARNING on drm/drm-next] [also build test WARNING on next-20160318] [cannot apply to v4.5] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] url: https://github.com/0day-ci/linux/commits/Joe-Perches/gpu-drm-Use-u64_to_user_pointer/20160319-012749 base: git://people.freedesktop.org/~airlied/linux.git drm-next config:

Hi, as Jason suggested some months ago, I looked better at the virtio-net driver to understand if we can reuse some parts also in the virtio-vsock driver, since we have similar challenges (mergeable buffers, page allocation, small packets, etc.). Initially, I would add the skbuff in the virtio-vsock in order to re-use receive_*() functions. Then I would move receive_[small, big, mergeable]() and