linux-kernel - Re: Fast memcpy patch

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAM_iQpVRzFtNOG8Y0nD3=Kw=N0-XcKVGdMd7sOWsgkdmt3jy9w@mail.gmail.com>
Date:	Wed, 23 Nov 2011 20:07:39 +0800
From:	Cong Wang <xiyou.wangcong@...il.com>
To:	"N. Coesel" <nico@...dev.nl>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Fast memcpy patch

On Wed, Nov 23, 2011 at 7:25 PM, N. Coesel <nico@...dev.nl> wrote:
> Dear readers,
> I noticed the Linux kernel still uses a byte-by-byte copy method for memcpy.
> Since most memory allocations are aligned to the integer size of a cpu it is
> often faster to copy by using the CPU's native word size. The patch below
> does that. The code is already at work in many 16 and 32 bit embedded
> products. It should also work for 64 bit platforms. So far I only tested 16
> and 32 bit platforms.

Which arch are you referring?

At least on x86, it has optimized memcpy(), see arch/x86/lib/memcpy_32.c
and arch/x86/include/asm/string_64.h.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/