Re: [RFC PATCH V3 0/5] Hi:

Jason Wang
2019-01-07T02:19:03Z

On 2019/1/3 上午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 with
> nosmap?
>

On machine without SMAP (Sandy Bridge):

Before: 4.8Mpps

After: 5.2Mpps

On machine with SMAP (Broadwell):

Before: 5.0Mpps

After: 6.1Mpps

No smap: 7.5Mpps

Thanks