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From:   Michael Ellerman <patch-notifications@ellerman.id.au>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
In-Reply-To: <af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu>
References: <af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu>
Subject: Re: [PATCH v2 1/2] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
Message-Id: <160483134413.1400561.8432797439436517862.b4-ty@ellerman.id.au>
Date:   Sun,  8 Nov 2020 21:29:39 +1100 (AEDT)
Precedence: bulk

On Mon, 12 Oct 2020 08:54:31 +0000 (UTC), Christophe Leroy wrote:
> The kernel expects pte_young() to work regardless of CONFIG_SWAP.
> 
> Make sure a minor fault is taken to set _PAGE_ACCESSED when it
> is not already set, regardless of the selection of CONFIG_SWAP.
> 
> This adds at least 3 instructions to the TLB miss exception
> handlers fast path. Following patch will reduce this overhead.
> 
> [...]

Applied to powerpc/fixes.

[1/2] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
      https://git.kernel.org/powerpc/c/29daf869cbab69088fe1755d9dd224e99ba78b56
[2/2] powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry
      https://git.kernel.org/powerpc/c/33fe43cfd9b1c20f6f9899b44bf04e91823ff1c9

cheers