linux-kernel - Re: [PATCH V3 1/2] arm64/mm: Consolidate page fault information capture

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Message-ID: <20190607133409.GJ16801@arrakis.emea.arm.com>
Date:   Fri, 7 Jun 2019 14:34:10 +0100
From:   Catalin Marinas <catalin.marinas@....com>
To:     Mark Rutland <mark.rutland@....com>
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        Will Deacon <will.deacon@....com>,
        James Morse <james.morse@....com>,
        Andrey Konovalov <andreyknvl@...gle.com>
Subject: Re: [PATCH V3 1/2] arm64/mm: Consolidate page fault information
 capture

On Fri, Jun 07, 2019 at 11:30:46AM +0100, Mark Rutland wrote:
> On Fri, Jun 07, 2019 at 02:43:05PM +0530, Anshuman Khandual wrote:
> > This consolidates page fault information capture and move them bit earlier.
> > While here it also adds an wrapper is_write_abort(). It also saves some
> > cycles by replacing multiple user_mode() calls into a single one earlier
> > during the fault.
> > 
> > Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
> > Cc: Catalin Marinas <catalin.marinas@....com>
> > Cc: Will Deacon <will.deacon@....com>
> > Cc: Mark Rutland <mark.rutland@....com>
> > Cc: James Morse <james.morse@....com>
> > Cc: Andrey Konovalov <andreyknvl@...gle.com>
> > ---
> >  arch/arm64/mm/fault.c | 26 +++++++++++++++++++-------
> >  1 file changed, 19 insertions(+), 7 deletions(-)
> 
> As I mentioned previously, I doubt that this has any measureable impact
> on performance, and other than commenting the caveats w.r.t. cache
> maintenance, I'm not sure this makes things any clearer.
> 
> However, AFAICT it is correct, so I'll leave that to Catalin:

I only merged the is_write_abort() wrapper from this patch (changed the
commit log as well).

-- 
Catalin