search for: copy_us

On 2019/1/3 ??4:47, Michael S. Tsirkin wrote: > On Sat, Dec 29, 2018 at 08:46:51PM +0800, Jason Wang wrote: >> 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. > Will review, thanks! > One questions that comes to mind is whether it's all about bypassing > stac/clac. Could you please include a performance comparison wi...

On 2019/1/3 ??4:47, Michael S. Tsirkin wrote: > On Sat, Dec 29, 2018 at 08:46:51PM +0800, Jason Wang wrote: >> 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. > Will review, thanks! > One questions that comes to mind is whether it's all about bypassing > stac/clac. Could you please include a performance comparison wi...

On 2019/3/8 ??10:12, Christoph Hellwig wrote: > On Wed, Mar 06, 2019 at 02:18:07AM -0500, Jason Wang wrote: >> 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 vmap() and >> resigter MMU notifier for invalidation. >> >> Test shows about 24% improvement on TX PPS. T...

On 2019/3/8 ??10:12, Christoph Hellwig wrote: > On Wed, Mar 06, 2019 at 02:18:07AM -0500, Jason Wang wrote: >> 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 vmap() and >> resigter MMU notifier for invalidation. >> >> Test shows about 24% improvement on TX PPS. T...

...:13:17PM +0800, Jason Wang wrote: >> >> On 2019/3/8 ??10:12, Christoph Hellwig wrote: >> > On Wed, Mar 06, 2019 at 02:18:07AM -0500, Jason Wang wrote: >> > > 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 vmap() and >> > > resigter MMU notifier for invalidation. >> > > >> >...

...:13:17PM +0800, Jason Wang wrote: >> >> On 2019/3/8 ??10:12, Christoph Hellwig wrote: >> > On Wed, Mar 06, 2019 at 02:18:07AM -0500, Jason Wang wrote: >> > > 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 vmap() and >> > > resigter MMU notifier for invalidation. >> > > >> >...

...07, 2019 at 10:19:03AM +0800, Jason Wang wrote: >> On 2019/1/3 ??4:47, Michael S. Tsirkin wrote: >>> On Sat, Dec 29, 2018 at 08:46:51PM +0800, Jason Wang wrote: >>>> 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. >>> Will review, thanks! >>> One questions that comes to mind is whether it's all about bypassing >>> stac/clac. Could you pl...

...07, 2019 at 10:19:03AM +0800, Jason Wang wrote: >> On 2019/1/3 ??4:47, Michael S. Tsirkin wrote: >>> On Sat, Dec 29, 2018 at 08:46:51PM +0800, Jason Wang wrote: >>>> 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. >>> Will review, thanks! >>> One questions that comes to mind is whether it's all about bypassing >>> stac/clac. Could you pl...

...wrote: >> On 2018/12/13 ??11:27, Michael S. Tsirkin wrote: >>> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >>>> 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. >>> Userspace accesses through remapping tricks and next time there's a need >>> for a new barrier we are left to figure it out by ours...

...wrote: >> On 2018/12/13 ??11:27, Michael S. Tsirkin wrote: >>> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >>>> 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. >>> Userspace accesses through remapping tricks and next time there's a need >>> for a new barrier we are left to figure it out by ours...

On 2018/12/14 ??4:12, Michael S. Tsirkin wrote: > On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >> 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. >> >> Test shows about 24% improvement on TX PPS. It should benefit other >> cases as well. >> >> Please review > I think the idea of speedi...

On 2018/12/14 ??4:12, Michael S. Tsirkin wrote: > On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >> 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. >> >> Test shows about 24% improvement on TX PPS. It should benefit other >> cases as well. >> >> Please review > I think the idea of speedi...

On Thu, May 30, 2019 at 11:07:30AM -0700, David Miller wrote: > From: Jason Wang <jasowang at redhat.com> > Date: Fri, 24 May 2019 04:12:12 -0400 > > > 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...

On 2018/12/13 ??11:27, Michael S. Tsirkin wrote: > On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >> 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. > Userspace accesses through remapping tricks and next time there's a need > for a new barrier we are left to figure it out by ourselves. I don't get here, d...

On 2018/12/13 ??11:27, Michael S. Tsirkin wrote: > On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >> 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. > Userspace accesses through remapping tricks and next time there's a need > for a new barrier we are left to figure it out by ourselves. I don't get here, d...

...Michael S. Tsirkin wrote: >>>>> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >>>>>> 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. >>>>> Userspace accesses through remapping tricks and next time there's a need >>>>> for a new barrier we a...

...Michael S. Tsirkin wrote: >>>>> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: >>>>>> 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. >>>>> Userspace accesses through remapping tricks and next time there's a need >>>>> for a new barrier we a...

...; > > On 2018/12/14 ??4:12, Michael S. Tsirkin wrote: > >> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: > >>> 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. > >>> > >>> Test shows about 24% improvement on TX PPS. It should benefit other > >>> cases as well. > >>>...

...; > > On 2018/12/14 ??4:12, Michael S. Tsirkin wrote: > >> On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: > >>> 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. > >>> > >>> Test shows about 24% improvement on TX PPS. It should benefit other > >>> cases as well. > >>>...

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. Test shows about 24% improvement on TX PPS. It should benefit other cases as well. Please review Jason Wang (3): vhost: generalize adding used elem vhost: fine grain userspace memory a...