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Subject: Re: [PATCH 7/8] membarrier: Remove arm (32) support for SYNC_CORE
To:     x86@kernel.org
Cc:     Dave Hansen <dave.hansen@intel.com>,
        LKML <linux-kernel@vger.kernel.org>, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Nicholas Piggin <npiggin@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Russell King <linux@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org
References: <cover.1623813516.git.luto@kernel.org>
 <2142129092ff9aa00e600c42a26c4015b7f5ceec.1623813516.git.luto@kernel.org>
From:   Andy Lutomirski <luto@kernel.org>
Message-ID: <f6674f8a-85ef-7a97-b8d8-575a57e47718@kernel.org>
Date:   Thu, 17 Jun 2021 17:07:04 -0700
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On 6/15/21 8:21 PM, Andy Lutomirski wrote:
> On arm32, the only way to safely flush icache from usermode is to call
> cacheflush(2).  This also handles any required pipeline flushes, so
> membarrier's SYNC_CORE feature is useless on arm.  Remove it.

After all the discussion, I'm dropping this patch.