------------------ Original ------------------
From: "Lorenzo Pieralisi" <lorenzo.pieralisi@linaro.org>;
Date: Sat, Dec 17, 2022 00:14 AM
To: "Zhangfei Gao"<zhangfei.gao@linaro.org>;
Cc: "Joyce Qi"<joyce.qi@linaro.org>;"jean-philippe"<jean-philippe@linaro.org>;"linaro-open-discussions"<linaro-open-discussions@op-lists.linaro.org>;"linux"<linux@armlinux.org.uk>;
Subject: Re: [Linaro-open-discussions] Re: Linaro-open-discussions Digest, Vol 25, Issue 3

On Thu, Oct 27, 2022 at 12:06:59PM +0800, Zhangfei Gao wrote:
> Hi, Lorenzo
>
> When we debug vsva, sva on guest with 2-stage translation,
> we found tlb miss impact performance a lot, with Jean's help.
>
> Currently we are using huge page feature in glibc to overcome this issue.
> With huge page, vsva in guest can achieve comparable performance as sva in
> host.
>
> More details: https://docs.qq.com/doc/DRXlpQmpTSlBZTGZZ
> Will do some
>
> Basically we are using two optimization methods/
> host sva: using memset fist to overcome io page fault, since cpu alloc
> physical memory is much faster than smmu.
> guest vsva: using huge page to overcome tlbmiss.
>
> The customer are asking whether (next version) silicon (smmu) can do some
> help to concur tlb miss issue or io page fault issue.

I can bring this up with the SMMU architect - thank you for taking
time to describe the use cases and SW you are deploying.

> If so, software can be simpler.
> Any suggestions?

Talking to SMMU architects - there is not much SW can do other than
what you are doing already.

Thanks,
Lorenzo

> Thanks
>
>
> On 2022/10/20 ÏÂÎç8:47, Joyce Qi via Linaro-open-discussions wrote:
> > Hi Jonathan,Lorenzo,all,
> >
> > Do we have any topic to sync on our LOD meeting next week?
> >
> > Thanks:)
> > Joyce
> >
> >
> >