search for: napi

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...

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...

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 is disabled and tx lock is held when changing the value of napi weight. And two more places that can acce...

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 is disabled and tx lock is held when changing the value of napi weight. And two more places that can acce...

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 cleani...

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 cleani...

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 ne...

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 ne...

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 (us...

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 (us...

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...

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...

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 ndo_start_xmit. Latency depends on new traffic, so > is unbounded. T...

...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 interrupt moderation, value 1 means tx napi while > value 0 means not. > > To properly synchronize with the data path, tx napi is disabled and > tx lock is held when changing the value of napi weight. And two m...

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...

...ertions(+), 36 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6b6e136..62c059d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -72,6 +72,8 @@ struct send_queue { /* Name of the send queue: output.$index */ char name[40]; + + struct napi_struct napi; }; /* Internal representation of a receive virtqueue */ @@ -211,15 +213,38 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) return p; } +static int free_old_xmit_skbs(struct send_queue *sq, int budget) +{ + struct sk_buff *skb; + unsigned int len; +...

...ertions(+), 36 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6b6e136..62c059d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -72,6 +72,8 @@ struct send_queue { /* Name of the send queue: output.$index */ char name[40]; + + struct napi_struct napi; }; /* Internal representation of a receive virtqueue */ @@ -211,15 +213,38 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) return p; } +static int free_old_xmit_skbs(struct send_queue *sq, int budget) +{ + struct sk_buff *skb; + unsigned int len; +...

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 (!napi->weight) >> + return; >> + >> + if (!vi->affi...

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 (!napi->weight) >> + return; >> + >> + if (!vi->affi...

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. Latency depends on new traffic, so > is unbounded. To...