linux-kernel - Re: Fast memcpy patch

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Message-ID: <1322050241.3581.15.camel@lappy>
Date:	Wed, 23 Nov 2011 14:10:41 +0200
From:	Sasha Levin <levinsasha928@...il.com>
To:	"N. Coesel" <nico@...dev.nl>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Fast memcpy patch

On Wed, 2011-11-23 at 12:25 +0100, N. Coesel 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.

[snip]

memcpy (along with other mem* functions) are arch specific - for
example, look at arch/x86/lib/memcpy_64.S for the implementation(s) for
x86.

The code under lib/string.c is simple and should work on all platforms
(and is probably not being used anywhere anymore).

-- 

Sasha.

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