[RFC PATCH V2 0/5] vhost: accelerate metadata access through vmap()

Jason Wang
Mon, 11 Mar 2019 07:13:17 -0000

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. TCP_STREAM doesn't see
>> obvious improvement.
> How is this going to work for CPUs with virtually tagged caches?


Anything different that you worry? I can have a test but do you know any
archs that use virtual tag cache?

Thanks