From: Folkert van Heusden <folkert@vanheusden.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: "Robert P. J. Day" <rpjday@mindspring.com>,
Denis Vlasenko <vda.linux@googlemail.com>,
Linux kernel mailing list <linux-kernel@vger.kernel.org>
Subject: Re: replace "memset(...,0,PAGE_SIZE)" calls with "clear_page()"?
Date: Sun, 31 Dec 2006 14:39:02 +0100 [thread overview]
Message-ID: <20061231133902.GA13521@vanheusden.com> (raw)
In-Reply-To: <1167518748.20929.578.camel@laptopd505.fenrus.org>
> > 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
next prev parent reply other threads:[~2006-12-31 13:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-29 6:16 replace "memset(...,0,PAGE_SIZE)" calls with "clear_page()"? Robert P. J. Day
2006-12-30 20:49 ` Denis Vlasenko
2006-12-30 22:08 ` Robert P. J. Day
2006-12-30 22:40 ` Denis Vlasenko
2007-01-03 6:23 ` dean gaudet
2006-12-30 22:45 ` Arjan van de Ven
2006-12-30 23:04 ` Robert P. J. Day
2006-12-31 18:39 ` Paul Mundt
2006-12-31 19:04 ` Robert P. J. Day
2007-01-01 1:59 ` Folkert van Heusden
2007-01-01 8:33 ` Robert P. J. Day
2007-01-01 10:14 ` Arjan van de Ven
2007-01-01 10:27 ` Robert P. J. Day
2007-01-01 19:05 ` Dave Jones
2007-01-01 8:42 ` Paul Mundt
2007-01-01 17:09 ` Randy Dunlap
2006-12-31 13:39 ` Folkert van Heusden [this message]
2006-12-31 13:45 ` Arjan van de Ven
2006-12-31 16:39 ` Robert P. J. Day
2006-12-31 17:43 ` Arjan van de Ven
2007-01-03 13:20 ` Robert P. J. Day
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20061231133902.GA13521@vanheusden.com \
--to=folkert@vanheusden.com \
--cc=arjan@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rpjday@mindspring.com \
--cc=vda.linux@googlemail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox