search for: virtio_f_event_idx

...t; On Sun, Apr 02, 2017 at 04:10:12PM -0400, Willem de Bruijn wrote: >> From: Willem de Bruijn <willemb at google.com> >> >> Amortize the cost of virtual interrupts by doing both rx and tx work >> on reception of a receive interrupt if tx napi is enabled. With >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion >> interrupts for bidirectional workloads. >> >> Signed-off-by: Willem de Bruijn <willemb at google.com> >> --- >> drivers/net/virtio_net.c | 22 ++++++++++++++++++++++ >> 1 file changed, 22 insertions(+) >&g...

...t; On Sun, Apr 02, 2017 at 04:10:12PM -0400, Willem de Bruijn wrote: >> From: Willem de Bruijn <willemb at google.com> >> >> Amortize the cost of virtual interrupts by doing both rx and tx work >> on reception of a receive interrupt if tx napi is enabled. With >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion >> interrupts for bidirectional workloads. >> >> Signed-off-by: Willem de Bruijn <willemb at google.com> >> --- >> drivers/net/virtio_net.c | 22 ++++++++++++++++++++++ >> 1 file changed, 22 insertions(+) >&g...

...Willem de Bruijn wrote: >> >> From: Willem de Bruijn <willemb at google.com> >> >> >> >> Amortize the cost of virtual interrupts by doing both rx and tx work >> >> on reception of a receive interrupt if tx napi is enabled. With >> >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion >> >> interrupts for bidirectional workloads. >> >> >> >> Signed-off-by: Willem de Bruijn <willemb at google.com> > > This is a popular approach, but I think this will only work well if tx > and rx inter...

...Willem de Bruijn wrote: >> >> From: Willem de Bruijn <willemb at google.com> >> >> >> >> Amortize the cost of virtual interrupts by doing both rx and tx work >> >> on reception of a receive interrupt if tx napi is enabled. With >> >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion >> >> interrupts for bidirectional workloads. >> >> >> >> Signed-off-by: Willem de Bruijn <willemb at google.com> > > This is a popular approach, but I think this will only work well if tx > and rx inter...

From: Willem de Bruijn <willemb at google.com> Amortize the cost of virtual interrupts by doing both rx and tx work on reception of a receive interrupt if tx napi is enabled. With VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion interrupts for bidirectional workloads. Signed-off-by: Willem de Bruijn <willemb at google.com> --- drivers/net/virtio_net.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio...

On Sun, Apr 02, 2017 at 04:10:12PM -0400, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb at google.com> > > Amortize the cost of virtual interrupts by doing both rx and tx work > on reception of a receive interrupt if tx napi is enabled. With > VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion > interrupts for bidirectional workloads. > > Signed-off-by: Willem de Bruijn <willemb at google.com> > --- > drivers/net/virtio_net.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drive...

...t 04:10:12PM -0400, Willem de Bruijn wrote: > >> From: Willem de Bruijn <willemb at google.com> > >> > >> Amortize the cost of virtual interrupts by doing both rx and tx work > >> on reception of a receive interrupt if tx napi is enabled. With > >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion > >> interrupts for bidirectional workloads. > >> > >> Signed-off-by: Willem de Bruijn <willemb at google.com> This is a popular approach, but I think this will only work well if tx and rx interrupts are processed on the...

...gt; >> >> From: Willem de Bruijn <willemb at google.com> > >> >> > >> >> Amortize the cost of virtual interrupts by doing both rx and tx work > >> >> on reception of a receive interrupt if tx napi is enabled. With > >> >> VIRTIO_F_EVENT_IDX, this suppresses most explicit tx completion > >> >> interrupts for bidirectional workloads. > >> >> > >> >> Signed-off-by: Willem de Bruijn <willemb at google.com> > > > > This is a popular approach, but I think this will only work wel...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...ugh. * Interrupt/event suppression virtio 1.0 has two mechanisms for suppression but only one can be used at a time. we pack them together in a structure - one for interrupts, one for notifications: struct event { __le16 idx; __le16 flags; } Both fields would be optional, with a feature bit: VIRTIO_F_EVENT_IDX VIRTIO_F_EVENT_FLAGS * Flags can be used like in virtio 1.0, by storing a special value there: #define VRING_F_EVENT_ENABLE 0x0 #define VRING_F_EVENT_DISABLE 0x1 * Event index would be in the range 0 to 2 * Queue Size (to detect wrap arounds) and wrap to 0 after that. The assumption is that e...

...ugh. * Interrupt/event suppression virtio 1.0 has two mechanisms for suppression but only one can be used at a time. we pack them together in a structure - one for interrupts, one for notifications: struct event { __le16 idx; __le16 flags; } Both fields would be optional, with a feature bit: VIRTIO_F_EVENT_IDX VIRTIO_F_EVENT_FLAGS * Flags can be used like in virtio 1.0, by storing a special value there: #define VRING_F_EVENT_ENABLE 0x0 #define VRING_F_EVENT_DISABLE 0x1 * Event index would be in the range 0 to 2 * Queue Size (to detect wrap arounds) and wrap to 0 after that. The assumption is that e...

...as two mechanisms for suppression but only > one can be used at a time. we pack them together > in a structure - one for interrupts, one for notifications: > > struct event { > __le16 idx; > __le16 flags; > } > > Both fields would be optional, with a feature bit: > VIRTIO_F_EVENT_IDX > VIRTIO_F_EVENT_FLAGS > > * Flags can be used like in virtio 1.0, by storing a special > value there: > > #define VRING_F_EVENT_ENABLE 0x0 > > #define VRING_F_EVENT_DISABLE 0x1 > > * Event index would be in the range 0 to 2 * Queue Size > (to detect wrap aroun...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...s TCP small queues. Reenable TCP small queues by removing the orphan. Instead of using a timer, convert the driver to regular tx napi. This does not have the unresolved stall issue and does not have any frequency to tune. By keeping interrupts enabled by default, napi increases tx interrupt rate. VIRTIO_F_EVENT_IDX avoids sending an interrupt if one is already unacknowledged, so makes this more feasible today. Combine that with an optimization that brings interrupt rate back in line with the existing version for most workloads: Tx completion cleaning on rx interrupts elides most explicit tx interrupts by rel...

...together > > > in a structure - one for interrupts, one for notifications: > > > > > > struct event { > > > __le16 idx; > > > __le16 flags; > > > } > > > > > > Both fields would be optional, with a feature bit: > > > VIRTIO_F_EVENT_IDX > > > VIRTIO_F_EVENT_FLAGS > > > > > > * Flags can be used like in virtio 1.0, by storing a special > > > value there: > > > > > > #define VRING_F_EVENT_ENABLE 0x0 > > > > > > #define VRING_F_EVENT_DISABLE 0x1 > > > &...

...together > > > in a structure - one for interrupts, one for notifications: > > > > > > struct event { > > > __le16 idx; > > > __le16 flags; > > > } > > > > > > Both fields would be optional, with a feature bit: > > > VIRTIO_F_EVENT_IDX > > > VIRTIO_F_EVENT_FLAGS > > > > > > * Flags can be used like in virtio 1.0, by storing a special > > > value there: > > > > > > #define VRING_F_EVENT_ENABLE 0x0 > > > > > > #define VRING_F_EVENT_DISABLE 0x1 > > > &...

...t; one can be used at a time. we pack them together > > in a structure - one for interrupts, one for notifications: > > > > struct event { > > __le16 idx; > > __le16 flags; > > } > > > > Both fields would be optional, with a feature bit: > > VIRTIO_F_EVENT_IDX > > VIRTIO_F_EVENT_FLAGS > > > > * Flags can be used like in virtio 1.0, by storing a special > > value there: > > > > #define VRING_F_EVENT_ENABLE 0x0 > > > > #define VRING_F_EVENT_DISABLE 0x1 > > > > * Event index would be in the ra...