Re: replace "memset(...,0,PAGE_SIZE)" calls with "clear_page()"?

From: Folkert van Heusden
Date: Sun Dec 31 2006 - 08:40:06 EST


> > i don't see how that can be true, given that most of the definitions
> > of the clear_page() macro are simply invocations of memset(). see for
> > yourself:
> *MOST*. Not all.
> For example an SSE version will at least assume 16 byte alignment, etc
> etc.

What about an if (adress & 15) { memset } else { sse stuff }
or is that too obvious? :-)

> clear_page() is supposed to be for full real pages only... for example
> it allows the architecture to optimize for alignment, cache aliasing etc
> etc. (and if there are cpus that get a "clear an entire page"
> instruction.... there has been hardware like that in the past, even on
> x86, just it's no longer sold afaik)


Folkert van Heusden

--
www.biglumber.com <- site where one can exchange PGP key signatures
----------------------------------------------------------------------
Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/