linux-kernel - Re: [PATCH v4 3/3] RISC-V: Issue a tlb page flush if possible

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Message-ID: <ab8e3417e7949390ce256fc4afb5d6e82e4f91da.camel@wdc.com>
Date:   Thu, 22 Aug 2019 18:31:29 +0000
From:   Atish Patra <Atish.Patra@....com>
To:     "hch@....de" <hch@....de>
CC:     "paul.walmsley@...ive.com" <paul.walmsley@...ive.com>,
        "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
        Anup Patel <Anup.Patel@....com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "palmer@...ive.com" <palmer@...ive.com>,
        "aou@...s.berkeley.edu" <aou@...s.berkeley.edu>
Subject: Re: [PATCH v4 3/3] RISC-V: Issue a tlb page flush if possible

On Thu, 2019-08-22 at 10:11 +0200, Christoph Hellwig wrote:
> On Thu, Aug 22, 2019 at 12:51:51AM -0700, Atish Patra wrote:
> > If tlbflush request is for page only, there is no need to do a
> > complete local tlb shootdown.
> > 
> > Just do a local tlb flush for the given address.
> 
> Looks good, although I suspect in many cases even doing multiple
> single-page sfence.vma calls might be cheaper than the global one.
> 
> But I think that is worth a ѕeparate discussion, preferably with
> actual
> numbers.
> 

Yup. Finding a good threashold is always tricky without real
benchmarks.

> Reviewed-by: Christoph Hellwig <hch@....de>

Thanks for the review.

-- 
Regards,
Atish