linux-kernel - Re: [PATCH v2 0/2] arm64/mm: Enable color zero pages

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Message-ID: <20200923084317.GA13434@gaia>
Date:   Wed, 23 Sep 2020 09:43:17 +0100
From:   Catalin Marinas <catalin.marinas@....com>
To:     Gavin Shan <gshan@...hat.com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        mark.rutland@....com, anshuman.khandual@....com,
        robin.murphy@....com, will@...nel.org, shan.gavin@...il.com
Subject: Re: [PATCH v2 0/2] arm64/mm: Enable color zero pages

Hi Gavin,

On Wed, Sep 23, 2020 at 03:37:19PM +1000, Gavin Shan wrote:
> The feature of color zero pages isn't enabled on arm64, meaning all
> read-only (anonymous) VM areas are backed up by same zero page. It
> leads pressure to L1 (data) cache on reading data from them. This
> tries to enable color zero pages.
> 
> PATCH[1/2] decouples the zero PGD table from zero page
> PATCH[2/2] allocates the needed zero pages according to L1 cache size

To save you (and potential reviewers) some time, please include in the
cover letter details of a realistic workload/benchmark that is improved
by this patchset, backed by numbers. Just because it's doable and the
patches aren't too complex is not a good enough reason for merging.

Thanks.

-- 
Catalin