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

From: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Will Deacon <will.deacon@arm.com>,
	James Morse <james.morse@arm.com>,
	Andrey Konovalov <andreyknvl@google.com>
Subject: Re: [PATCH V3 1/2] arm64/mm: Consolidate page fault information capture
Date: Fri, 7 Jun 2019 14:34:10 +0100	[thread overview]
Message-ID: <20190607133409.GJ16801@arrakis.emea.arm.com> (raw)
In-Reply-To: <20190607103045.GB15753@lakrids.cambridge.arm.com>

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@arm.com>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: James Morse <james.morse@arm.com>
> > Cc: Andrey Konovalov <andreyknvl@google.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