Date: Tue, 15 Dec 2015 19:39:24 +0100
From: Borislav Petkov <bp@alien8.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>, Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>, linux-nvdimm <linux-nvdimm@ml01.01.org>,
        X86 ML <x86@kernel.org>
Subject: Re: [PATCHV2 3/3] x86, ras: Add mcsafe_memcpy() function to recover
 from machine checks
Message-ID: <20151215183924.GJ25973@pd.tnic>
References: <cover.1449861203.git.tony.luck@intel.com>
 <23b2515da9d06b198044ad83ca0a15ba38c24e6e.1449861203.git.tony.luck@intel.com>
 <20151215131135.GE25973@pd.tnic>
 <CAPcyv4gMr6LcZqjxt6fAoEiaa0AzcgMxnp2+V=TWJ1eHb6nC3A@mail.gmail.com>
 <3908561D78D1C84285E8C5FCA982C28F39F8566E@ORSMSX114.amr.corp.intel.com>
 <CAPcyv4icSmdnvQhsdzfP3uZYXJ2vsjrZxMQjSghNOt19u++o7g@mail.gmail.com>
 <CAPcyv4gMku=rAczAz2b4PaW6qwm9LAVU8BG3hcT_A4QMAkZfbA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <CAPcyv4gMku=rAczAz2b4PaW6qwm9LAVU8BG3hcT_A4QMAkZfbA@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 658
Lines: 17

On Tue, Dec 15, 2015 at 10:35:49AM -0800, Dan Williams wrote:
> Correction we have MOVNTDQA, but that requires saving the fpu state
> and marking the memory as WC, i.e. probably not worth it.

Not really. Last time I tried an SSE3 memcpy in the kernel like glibc
does, it wasn't worth it. The enhanced REP; MOVSB is hands down faster.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/