similar to: [PATCH v3 0/4] virtio net: spurious interrupt related fixes

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

On Fri, Mar 24, 2023 at 02:47:02PM +0800, Jason Wang wrote: > On Fri, Mar 24, 2023 at 2:42?PM Michael S. Tsirkin <mst at redhat.com> wrote: > > > > On Fri, Mar 24, 2023 at 02:32:40PM +0800, Jason Wang wrote: > > > On Fri, Mar 24, 2023 at 1:59?PM Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > > > > On Fri, Mar 24, 2023 at

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

Hello all: We free old transmitted packets in ndo_start_xmit() currently, so any packet must be orphaned also there. This was used to reduce the overhead of tx interrupt to achieve better performance. But this may not work for some protocols such as TCP stream. TCP depends on the value of sk_wmem_alloc to implement various optimization for small packets stream such as TCP small queue and auto

Hello all: We free old transmitted packets in ndo_start_xmit() currently, so any packet must be orphaned also there. This was used to reduce the overhead of tx interrupt to achieve better performance. But this may not work for some protocols such as TCP stream. TCP depends on the value of sk_wmem_alloc to implement various optimization for small packets stream such as TCP small queue and auto

At the moment, if a network device uses vrings with less than MAX_SKB_FRAGS + 2 entries, the device won't be functional. The following condition vq->num_free >= 2 + MAX_SKB_FRAGS will always evaluate to false, leading to TX timeouts. This patch introduces a new variable, single_pkt_max_descs, that holds the max number of descriptors we may need to handle a single packet. This patch

According to David, proper accounting and queueing (at all levels, not just TCP sockets) is more important than trying to skim a bunch of cycles by avoiding TX interrupts. Having an event to free the SKB is absolutely essential for the stack to operate correctly. This series tries to enable tx interrupt for virtio-net. The idea is simple: enable tx interrupt and schedule a tx napi to free old

According to David, proper accounting and queueing (at all levels, not just TCP sockets) is more important than trying to skim a bunch of cycles by avoiding TX interrupts. Having an event to free the SKB is absolutely essential for the stack to operate correctly. This series tries to enable tx interrupt for virtio-net. The idea is simple: enable tx interrupt and schedule a tx napi to free old

Hi: This is a new version of trying to enable tx interrupts for virtio-net. We used to try to avoid tx interrupts and orphan packets before transmission for virtio-net. This breaks socket accounting and can lead serveral other side effects e.g: - Several other functions which depends on socket accounting can not work correctly (e.g TCP Small Queue) - No tx completion which make BQL or

Hi: This is a new version of trying to enable tx interrupts for virtio-net. We used to try to avoid tx interrupts and orphan packets before transmission for virtio-net. This breaks socket accounting and can lead serveral other side effects e.g: - Several other functions which depends on socket accounting can not work correctly (e.g TCP Small Queue) - No tx completion which make BQL or

On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: > When use_napi is set, let's enable BQLs. Note: some of the issues are > similar to wifi. It's worth considering whether something similar to > commit 36148c2bbfbe ("mac80211: Adjust TSQ pacing shift") might be > benefitial. I've played a similar patch several days before. The tricky part is the mode switching

On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: > When use_napi is set, let's enable BQLs. Note: some of the issues are > similar to wifi. It's worth considering whether something similar to > commit 36148c2bbfbe ("mac80211: Adjust TSQ pacing shift") might be > benefitial. I've played a similar patch several days before. The tricky part is the mode switching

Now that we have brought the virtio overhead way down with a fast packed ring implementation, we seem to be actually observing TCP drops indicative of bufferbloat. So let's try to enable TSQ. Note: it isn't clear that the default pacing is great for the virt usecase. It's worth trying to play with sk_pacing_shift_update to see what happens. For this reason, and for a more important

On 2018/12/26 ??11:22, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

On 2018/12/26 ??11:22, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

Hi: This is a new version of trying to enable tx interrupts for virtio-net. We used to try to avoid tx interrupts and orphan packets before transmission for virtio-net. This breaks socket accounting and can lead serveral other side effects e.g: - Several other functions which depends on socket accounting can not work correctly (e.g TCP Small Queue) - No tx completion which make BQL or packet