similar to: [PATCH 0/2] Revert and rework on the metadata accelreation

On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: > This is a rework on the commit 7f466032dc9e ("vhost: access vq > metadata through kernel virtual address"). > > It was noticed that the copy_to/from_user() friends that was used to > access virtqueue metdata tends to be very expensive for dataplane > implementation like vhost since it involves lots of

On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: > This is a rework on the commit 7f466032dc9e ("vhost: access vq > metadata through kernel virtual address"). > > It was noticed that the copy_to/from_user() friends that was used to > access virtqueue metdata tends to be very expensive for dataplane > implementation like vhost since it involves lots of

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the range is overlapped with metadata Jason Wang (9):

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V1: - Try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the range is overlapped with metadata Jason Wang (9): vhost: don't set uaddr for invalid address vhost: validate MMU notifier

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V4: - switch to use spinlock synchronize MMU notifier with accessors Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V4: - switch to use spinlock synchronize MMU notifier with accessors Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost

On Thu, Sep 05, 2019 at 08:27:35PM +0800, Jason Wang wrote: > It was reported that metadata acceleration introduces several issues, > so this patch reverts commit ff466032dc9e5a61217f22ea34b2df932786bbfc, > 73f628ec9e6bcc45b77c53fe6d0c0ec55eaf82af and > 0b4a7092ffe568a55bf8f3cefdf79ff666586d91. > > We will rework it on the next version. > > Cc: Jason Gunthorpe <jgg at

On Wed, Jul 31, 2019 at 04:46:53AM -0400, Jason Wang wrote: > We used to use RCU to synchronize MMU notifier with worker. This leads > calling synchronize_rcu() in invalidate_range_start(). But on a busy > system, there would be many factors that may slow down the > synchronize_rcu() which makes it unsuitable to be called in MMU > notifier. > > A solution is SRCU but its

On Wed, Jul 31, 2019 at 04:46:53AM -0400, Jason Wang wrote: > We used to use RCU to synchronize MMU notifier with worker. This leads > calling synchronize_rcu() in invalidate_range_start(). But on a busy > system, there would be many factors that may slow down the > synchronize_rcu() which makes it unsuitable to be called in MMU > notifier. > > A solution is SRCU but its

On Thu, Aug 01, 2019 at 04:06:13AM -0400, Jason Wang wrote: > On 2019/8/1 ??2:29, Michael S. Tsirkin wrote: > > On Wed, Jul 31, 2019 at 04:46:53AM -0400, Jason Wang wrote: > >> We used to use RCU to synchronize MMU notifier with worker. This leads > >> calling synchronize_rcu() in invalidate_range_start(). But on a busy > >> system, there would be many factors

Hi: This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling like SMAP. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM

Hi: This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling like SMAP. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Jason Wang (6): vhost: don't set uaddr for invalid address vhost: validate MMU notifier registration vhost: fix vhost map leak vhost: reset invalidate_count in vhost_set_vring_num_addr() vhost: mark dirty pages during map uninit vhost: don't do synchronize_rcu() in

This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM doesn't see obvious

On Wed, Aug 07, 2019 at 03:06:15AM -0400, Jason Wang wrote: > We used to use RCU to synchronize MMU notifier with worker. This leads > calling synchronize_rcu() in invalidate_range_start(). But on a busy > system, there would be many factors that may slow down the > synchronize_rcu() which makes it unsuitable to be called in MMU > notifier. > > So this patch switches use

On Wed, Aug 07, 2019 at 03:06:15AM -0400, Jason Wang wrote: > We used to use RCU to synchronize MMU notifier with worker. This leads > calling synchronize_rcu() in invalidate_range_start(). But on a busy > system, there would be many factors that may slow down the > synchronize_rcu() which makes it unsuitable to be called in MMU > notifier. > > So this patch switches use

On Tue, Jul 23, 2019 at 03:57:17AM -0400, Jason Wang wrote: > We don't mark dirty pages if the map was teared down outside MMU > notifier. This will lead untracked dirty pages. Fixing by marking > dirty pages during map uninit. > > Reported-by: Michael S. Tsirkin <mst at redhat.com> > Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual

On Tue, Jul 23, 2019 at 03:57:17AM -0400, Jason Wang wrote: > We don't mark dirty pages if the map was teared down outside MMU > notifier. This will lead untracked dirty pages. Fixing by marking > dirty pages during map uninit. > > Reported-by: Michael S. Tsirkin <mst at redhat.com> > Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual