search for: napis

From: Willem de Bruijn <willemb at google.com> As of tx napi, device down (`ip link set dev $dev down`) hangs unless tx napi is enabled. Else napi_enable is not called, so napi_disable will spin on test_and_set_bit NAPI_STATE_SCHED. Only call napi_disable if tx napi is enabled. Fixes: 5a719c2552ca ("virtio-net: transmit napi") Reported-by: Jason Wang <jasowang at

From: Willem de Bruijn <willemb at google.com> As of tx napi, device down (`ip link set dev $dev down`) hangs unless tx napi is enabled. Else napi_enable is not called, so napi_disable will spin on test_and_set_bit NAPI_STATE_SCHED. Only call napi_disable if tx napi is enabled. Fixes: 5a719c2552ca ("virtio-net: transmit napi") Reported-by: Jason Wang <jasowang at

Implement ethtool .set_coalesce (-C) and .get_coalesce (-c) handlers. Interrupt moderation is currently not supported, so these accept and display the default settings of 0 usec and 1 frame. Toggle tx napi through a bit in tx-frames. So as to not interfere with possible future interrupt moderation, value 1 means tx napi while value 0 means not. To properly synchronize with the data path, tx napi

Implement ethtool .set_coalesce (-C) and .get_coalesce (-c) handlers. Interrupt moderation is currently not supported, so these accept and display the default settings of 0 usec and 1 frame. Toggle tx napi through a bit in tx-frames. So as to not interfere with possible future interrupt moderation, value 1 means tx napi while value 0 means not. To properly synchronize with the data path, tx napi

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Changes: v1 -> v2: - disable by default - disable unless affinity_hint_set because cache misses add up to a third higher cycle cost, e.g., in TCP_RR tests. This is not limited to the patch that enables tx completion cleaning in rx napi. - use trylock to

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Changes: v1 -> v2: - disable by default - disable unless affinity_hint_set because cache misses add up to a third higher cycle cost, e.g., in TCP_RR tests. This is not limited to the patch that enables tx completion cleaning in rx napi. - use trylock to

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Based on previous patchsets by Jason Wang: [RFC V7 PATCH 0/7] enable tx interrupts for virtio-net http://lkml.iu.edu/hypermail/linux/kernel/1505.3/00245.html Changes: RFC -> v1: - dropped vhost interrupt moderation patch: not needed and likely expensive at light

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Based on previous patchsets by Jason Wang: [RFC V7 PATCH 0/7] enable tx interrupts for virtio-net http://lkml.iu.edu/hypermail/linux/kernel/1505.3/00245.html Changes: RFC -> v1: - dropped vhost interrupt moderation patch: not needed and likely expensive at light

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Changes: v2 -> v3: - convert __netif_tx_trylock to __netif_tx_lock on tx napi poll ensure that the handler always cleans, to avoid deadlock - unconditionally clean in start_xmit avoid adding an unnecessary "if (use_napi)" branch - remove

From: Willem de Bruijn <willemb at google.com> Add napi for virtio-net transmit completion processing. Changes: v2 -> v3: - convert __netif_tx_trylock to __netif_tx_lock on tx napi poll ensure that the handler always cleans, to avoid deadlock - unconditionally clean in start_xmit avoid adding an unnecessary "if (use_napi)" branch - remove

From: Willem de Bruijn <willemb at google.com> Convert virtio-net to a standard napi tx completion path. This enables better TCP pacing using TCP small queues and increases single stream throughput. The virtio-net driver currently cleans tx descriptors on transmission of new packets in ndo_start_xmit. Latency depends on new traffic, so is unbounded. To avoid deadlock when a socket reaches

From: Willem de Bruijn <willemb at google.com> Convert virtio-net to a standard napi tx completion path. This enables better TCP pacing using TCP small queues and increases single stream throughput. The virtio-net driver currently cleans tx descriptors on transmission of new packets in ndo_start_xmit. Latency depends on new traffic, so is unbounded. To avoid deadlock when a socket reaches

On Sun, Apr 02, 2017 at 04:10:11PM -0400, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb at google.com> > > Convert virtio-net to a standard napi tx completion path. This enables > better TCP pacing using TCP small queues and increases single stream > throughput. > > The virtio-net driver currently cleans tx descriptors on transmission > of new packets in

On Thu, Sep 13, 2018 at 1:40 AM Jason Wang <jasowang at redhat.com> wrote: > > Implement ethtool .set_coalesce (-C) and .get_coalesce (-c) handlers. > Interrupt moderation is currently not supported, so these accept and > display the default settings of 0 usec and 1 frame. > > Toggle tx napi through a bit in tx-frames. So as to not interfere > with possible future

From: Willem de Bruijn <willemb at google.com> Convert virtio-net to a standard napi tx completion path. This enables better TCP pacing using TCP small queues and increases single stream throughput. The virtio-net driver currently cleans tx descriptors on transmission of new packets in ndo_start_xmit. Latency depends on new traffic, so is unbounded. To avoid deadlock when a socket reaches

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this will likely degrade performance for hosts without event idx support. Various fallback options are available, including orphaning conditionally. Testing TBD. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this will likely degrade performance for hosts without event idx support. Various fallback options are available, including orphaning conditionally. Testing TBD. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

On Thu, Apr 20, 2017 at 2:27 AM, Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?04?19? 04:21, Willem de Bruijn wrote: >> >> +static void virtnet_napi_tx_enable(struct virtnet_info *vi, >> + struct virtqueue *vq, >> + struct napi_struct *napi) >> +{ >> + if

On Thu, Apr 20, 2017 at 2:27 AM, Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?04?19? 04:21, Willem de Bruijn wrote: >> >> +static void virtnet_napi_tx_enable(struct virtnet_info *vi, >> + struct virtqueue *vq, >> + struct napi_struct *napi) >> +{ >> + if

On 2017?04?19? 04:21, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb at google.com> > > Convert virtio-net to a standard napi tx completion path. This enables > better TCP pacing using TCP small queues and increases single stream > throughput. > > The virtio-net driver currently cleans tx descriptors on transmission > of new packets in ndo_start_xmit.