>-----Original Message----- >From: Peter Xu <pet...@redhat.com> >Sent: Saturday, June 10, 2023 5:26 AM >Subject: Re: [PATCH v3 5/5] intel_iommu: Optimize out some unnecessary >UNMAP calls > >On Fri, Jun 09, 2023 at 05:49:06AM +0000, Duan, Zhenzhong wrote: >> Seems vtd_page_walk_one() already works in above way, checking mapping >> changes and calling kernel for changed entries? > >Agreed in most cases, but the path this patch modified is not? E.g. it happens >in rare cases where we simply want to unmap everything (e.g. on a system >reset, or invalid context entry)? Clear.
> >That's also why I'm curious whether perf of this path matters at all (and >assuming now we all agree that's the only goal now..), because afaiu it didn't >really trigger in common paths. I'll collect performance data and reply back. Thanks Zhenzhong