similar to: [PATCHv2 00/14] virtio and vhost-net performance enhancements

OK, here's a large patchset that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. I know it's a lot to ask but please test, and please consider for 2.6.40 :) I see nice performance improvements: one run showed going from 12 to 18 Gbit/s host to guest with netperf, but I did not spend a lot of time testing performance,

OK, here's a large patchset that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. I know it's a lot to ask but please test, and please consider for 2.6.40 :) I see nice performance improvements: one run showed going from 12 to 18 Gbit/s host to guest with netperf, but I did not spend a lot of time testing performance,

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run

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

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

Hi all: This RFC implement a subset of packed ring which was described at https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd07.pdf . The code were tested with pmd implement by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html. Minor change was needed for pmd codes to kick virtqueue since it assumes a busy polling backend. Test were done between localhost

Hi all: This RFC implement a subset of packed ring which was described at https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd07.pdf . The code were tested with pmd implement by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html. Minor change was needed for pmd codes to kick virtqueue since it assumes a busy polling backend. Test were done between localhost

OK, here's a new attempt to use the new capacity api. I also added more comments to clarify the logic. Hope this is more readable. Let me know pls. This is on top of the patches applied by Rusty. Warning: untested. Posting now to give people chance to comment on the API. Changes from v1: - fix comment in patch 2 to correct confusion noted by Rusty - rewrite patch 3 along the lines

OK, here's a new attempt to use the new capacity api. I also added more comments to clarify the logic. Hope this is more readable. Let me know pls. This is on top of the patches applied by Rusty. Warning: untested. Posting now to give people chance to comment on the API. Changes from v1: - fix comment in patch 2 to correct confusion noted by Rusty - rewrite patch 3 along the lines

Hi all: This RFC implement packed ring layout. The code were tested with pmd implement by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html. Minor change was needed for pmd codes to kick virtqueue since it assumes a busy polling backend. Test were done between localhost and guest. Testpmd (rxonly) in guest reports 2.4Mpps. Testpmd (txonly) repots about 2.1Mpps. Notes: The event

Hi all: This RFC implement packed ring layout. The code were tested with pmd implement by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html. Minor change was needed for pmd codes to kick virtqueue since it assumes a busy polling backend. Test were done between localhost and guest. Testpmd (rxonly) in guest reports 2.4Mpps. Testpmd (txonly) repots about 2.1Mpps. Notes: The event

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and tweaks were needed on top of Tiwei's code to make it run. TCP stream and pktgen does not show obvious difference compared with split ring. Changes from V2: - do not use & in checking desc_event_flags - off should be most significant bit -

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and tweaks were needed on top of Tiwei's code to make it run. TCP stream and pktgen does not show obvious difference compared with split ring. Changes from V2: - do not use & in checking desc_event_flags - off should be most significant bit -

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V5 at https://lkml.org/lkml/2018/5/22/138. Some fixups and tweaks were needed on top of Tiwei's code to make it run for event index. Pktgen reports about 20% improvement on TX PPS when doing pktgen from guest to host. No ovbious improvement on RX PPS. We can do lots of optimizations on top but for simple

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

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

Below should be useful for some experiments Jason is doing. I thought I'd send it out for early review/feedback. Compiled-only at this point. event idx feature allows us to defer interrupts until a specific # of descriptors were used. Sometimes it might be useful to get an interrupt after a specific descriptor, regardless. This adds a descriptor flag for this, and an API to create an urgent