From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [RFC PATCH V2 0/5] vhost: accelerate metadata access through
 vmap()
Date: Fri, 8 Mar 2019 06:12:20 -0800
Message-ID: <20190308141220.GA21082@infradead.org>
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To: Jason Wang <jasowang@redhat.com>
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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?