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;
Date:   Tue, 26 Jan 2021 23:08:52 +0000
From:   Will Deacon <will@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jan Kara <jack@suse.cz>, Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Vinayak Menon <vinmenon@codeaurora.org>,
        Hugh Dickins <hughd@google.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        kernel-team@android.com
Subject: Re: [PATCH v4 0/8] Create 'old' ptes for faultaround mappings on
 arm64 with hardware access flag
Message-ID: <20210126230851.GE30941@willie-the-truck>
References: <20210120173612.20913-1-will@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210120173612.20913-1-will@kernel.org>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Wed, Jan 20, 2021 at 05:36:04PM +0000, Will Deacon wrote:
> Hi all,
> 
> This is version four of the patches I previously posted here:
> 
>   v1: https://lore.kernel.org/r/20201209163950.8494-1-will@kernel.org
>   v2: https://lore.kernel.org/r/20210108171517.5290-1-will@kernel.org
>   v3: https://lore.kernel.org/r/20210114175934.13070-1-will@kernel.org
> 
> The patches allow architectures to opt-in at runtime for faultaround
> mappings to be created as 'old' instead of 'young'. Although there have
> been previous attempts at this, they failed either because the decision
> was deferred to userspace [1] or because it was done unconditionally and
> shown to regress benchmarks for particular architectures [2].
> 
> The big change since v3 is that the immutable fields of 'struct vm_fault'
> now live in a 'const' anonymous struct. Although Clang will silently
> accept modifications to these fields [3], GCC emits an error. The
> resulting diffstat is _considerably_ more manageable with this approach.

The only changes I have pending against this series are cosmetic (commit
logs). Can I go ahead and queue this in the arm64 tree so that it can sit
in linux-next for a bit? (positive or negative feedback appreciated!).

Thanks,

Will