linux-kernel - replace "memset(...,0,PAGE_SIZE)" calls with "clear

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Date:	Fri, 29 Dec 2006 01:16:07 -0500 (EST)
From:	"Robert P. J. Day" <rpjday@...dspring.com>
To:	Linux kernel mailing list <linux-kernel@...r.kernel.org>
Subject: replace "memset(...,0,PAGE_SIZE)" calls with "clear_page()"?

  is there some reason there are so many calls of the form

  memset(addr, 0, PAGE_SIZE)

rather than the apparently equivalent invocation of

  clear_page(addr)

the majority of architectures appear to define the clear_page() macro
in their include/<arch>/page.h header file, but not entirely
identically, and in some cases that definition is conditional, as with
i386:

=============================================================
#ifdef CONFIG_X86_USE_3DNOW
...
#define clear_page(page)        mmx_clear_page((void *)(page))
...
#else
...
#define clear_page(page)        memset((void *)(page), 0, PAGE_SIZE)
...
#endif
============================================================

  should it perhaps be part of the CodingStyle doc to use the
clear_page() macro rather than an explicit call to memset()?  (and
should all architectures be required to define that macro?)

rday
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