Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <1599116482-7410-1-git-send-email-alex.shi@linux.alibaba.com> <1599116482-7410-3-git-send-email-alex.shi@linux.alibaba.com>
In-Reply-To: <1599116482-7410-3-git-send-email-alex.shi@linux.alibaba.com>
From:   Max Filippov <jcmvbkbc@gmail.com>
Date:   Thu, 3 Sep 2020 00:29:16 -0700
Message-ID: <CAMo8BfJT7JJfwT1-X3vfqKGD-E3-Dbf2xyWs-RiRyUUHmbetVA@mail.gmail.com>
Subject: Re: [PATCH v4 3/4] mm/pageblock: work around multiple arch's cmpxchg
 support issue
To:     Alex Shi <alex.shi@linux.alibaba.com>
Cc:     Anshuman Khandual <anshuman.khandual@arm.com>,
        David Hildenbrand <david@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Alexander Duyck <alexander.duyck@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Russell King <linux@armlinux.org.uk>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>,
        "David S. Miller" <davem@davemloft.net>,
        Chris Zankel <chris@zankel.net>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        "open list:SUPERH" <linux-sh@vger.kernel.org>,
        "open list:SPARC + UltraSPAR..." <sparclinux@vger.kernel.org>,
        "open list:TENSILICA XTENSA PORT (xtensa)" 
        <linux-xtensa@linux-xtensa.org>,
        Linux Memory Management List <linux-mm@kvack.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Sep 3, 2020 at 12:01 AM Alex Shi <alex.shi@linux.alibaba.com> wrote:
>
> Armv6, sh2, sparc32 and xtensa can not do cmpxchg1, so we have to use
> cmpxchg4 on it.

[...]

> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig> index e00d94b16658..03a6c7fd999d 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -48,6 +48,7 @@ config ARM
>         select GENERIC_ALLOCATOR
>         select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
>         select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
> +       select NO_CMPXCHG_BYTE if CPU_V6
>         select GENERIC_CLOCKEVENTS_BROADCAST if SMP
>         select GENERIC_CPU_AUTOPROBE
>         select GENERIC_EARLY_IOREMAP
> diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> index d20927128fce..4c7f0ad5b93f 100644
> --- a/arch/sh/Kconfig
> +++ b/arch/sh/Kconfig
> @@ -155,6 +155,7 @@ menu "System type"
>  config CPU_SH2
>         bool
>         select SH_INTC
> +       select NO_CMPXCHG_BYTE
>
>  config CPU_SH2A
>         bool
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index efeff2c896a5..51ae5c8ede87 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -58,6 +58,7 @@ config SPARC32
>         select CLZ_TAB
>         select HAVE_UID16
>         select OLD_SIGACTION
> +       select NO_CMPXCHG_BYTE
>
>  config SPARC64
>         def_bool 64BIT
> diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
> index e997e0119c02..862b008ab09e 100644
> --- a/arch/xtensa/Kconfig
> +++ b/arch/xtensa/Kconfig
> @@ -42,6 +42,7 @@ config XTENSA
>         select MODULES_USE_ELF_RELA
>         select PERF_USE_VMALLOC
>         select VIRT_TO_BUS
> +       select NO_CMPXCHG_BYTE

Please keep the lists of select statements in Kconfig files above
alphabetically sorted.

-- 
Thanks.
-- Max