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From: Catalin Marinas <catalin.marinas@arm.com>
To: Peter Collingbourne <pcc@google.com>
Cc: andreyknvl@gmail.com, linux-mm@kvack.org,
	kasan-dev@googlegroups.com, ryabinin.a.a@gmail.com,
	linux-arm-kernel@lists.infradead.org, vincenzo.frascino@arm.com,
	will@kernel.org, eugenis@google.com
Subject: Re: [PATCH v2] kasan: call clear_page with a match-all tag instead of changing page tag
Date: Mon, 20 Feb 2023 15:54:51 +0000	[thread overview]
Message-ID: <Y/OXy3pQQDUybAgH@arm.com> (raw)
In-Reply-To: <20230216195924.3287772-1-pcc@google.com>

On Thu, Feb 16, 2023 at 11:59:24AM -0800, Peter Collingbourne wrote:
> Instead of changing the page's tag solely in order to obtain a pointer
> with a match-all tag and then changing it back again, just convert the
> pointer that we get from kmap_atomic() into one with a match-all tag
> before passing it to clear_page().
> 
> On a certain microarchitecture, this has been observed to cause a
> measurable improvement in microbenchmark performance, presumably as a
> result of being able to avoid the atomic operations on the page tag.
> 
> Signed-off-by: Peter Collingbourne <pcc@google.com>
> Link: https://linux-review.googlesource.com/id/I0249822cc29097ca7a04ad48e8eb14871f80e711

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

Not sure how this will go upstream, maybe the mm tree? Otherwise happy
to take it through the arm64 tree.

Thanks.

-- 
Catalin


      parent reply	other threads:[~2023-02-20 15:55 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-16 19:59 Peter Collingbourne
2023-02-17  9:56 ` Andrey Konovalov
2023-02-20 15:54 ` Catalin Marinas [this message]

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