From: Arjan van de Ven <arjan@infradead.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Andi Kleen <andi@firstfloor.org>,
David Miller <davem@davemloft.net>,
torvalds@linux-foundation.org, mingo@elte.hu,
nickpiggin@yahoo.com.au, sqazi@google.com,
linux-kernel@vger.kernel.org, tglx@linutronix.de
Subject: Re: [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache()
Date: Sat, 28 Feb 2009 17:38:13 -0800 [thread overview]
Message-ID: <20090228173813.6d86c0ef@infradead.org> (raw)
In-Reply-To: <20090301014822.GG26292@one.firstfloor.org>
On Sun, 1 Mar 2009 02:48:22 +0100
Andi Kleen <andi@firstfloor.org> wrote:
> > the entire point of using movntq and friends was to save half the
>
> I thought the point was to not pollute caches? At least that is
> what I remember being told when I merged the patch.
>
the reason that movntq and co are faster is because you avoid the
write-allocate behavior of the caches....
the cache polluting part of it I find hard to buy for general use (as
this discussion shows)... that will be extremely hard to measure as
a real huge thing, while the WA part is like a 1.5x to 2x thing.
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2009-03-01 1:38 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-24 2:03 Performance regression in write() syscall Salman Qazi
2009-02-24 4:10 ` Nick Piggin
2009-02-24 4:28 ` Linus Torvalds
2009-02-24 9:02 ` Nick Piggin
2009-02-24 15:52 ` Linus Torvalds
2009-02-24 16:24 ` Andi Kleen
2009-02-24 16:51 ` Ingo Molnar
2009-02-25 3:23 ` Nick Piggin
2009-02-25 7:25 ` [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache() Ingo Molnar
2009-02-25 8:09 ` Nick Piggin
2009-02-25 8:29 ` Ingo Molnar
2009-02-25 8:59 ` Nick Piggin
2009-02-25 12:01 ` Ingo Molnar
2009-02-25 16:04 ` Linus Torvalds
2009-02-25 16:29 ` Ingo Molnar
2009-02-27 12:05 ` Nick Piggin
2009-02-28 8:29 ` Ingo Molnar
2009-02-28 11:49 ` Nick Piggin
2009-02-28 12:58 ` Ingo Molnar
2009-02-28 17:16 ` Linus Torvalds
2009-02-28 17:24 ` Arjan van de Ven
2009-02-28 17:42 ` Linus Torvalds
2009-02-28 17:53 ` Arjan van de Ven
2009-02-28 18:05 ` Andi Kleen
2009-02-28 18:27 ` Ingo Molnar
2009-02-28 18:39 ` Arjan van de Ven
2009-03-02 10:39 ` [PATCH] x86, mm: dont use non-temporal stores in pagecache accesses Ingo Molnar
2009-02-28 18:52 ` [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache() Linus Torvalds
2009-03-01 14:19 ` Nick Piggin
2009-03-01 0:06 ` David Miller
2009-03-01 0:40 ` Andi Kleen
2009-03-01 0:28 ` H. Peter Anvin
2009-03-01 0:38 ` Arjan van de Ven
2009-03-01 1:48 ` Andi Kleen
2009-03-01 1:38 ` Arjan van de Ven [this message]
2009-03-01 1:40 ` H. Peter Anvin
2009-03-01 14:06 ` Nick Piggin
2009-03-02 4:46 ` H. Peter Anvin
2009-03-02 6:18 ` Nick Piggin
2009-03-02 21:16 ` Linus Torvalds
2009-03-02 21:25 ` Ingo Molnar
2009-03-03 4:30 ` Nick Piggin
2009-03-03 4:20 ` Nick Piggin
2009-03-03 9:02 ` Ingo Molnar
2009-03-04 3:37 ` Nick Piggin
2009-03-01 2:07 ` Andi Kleen
2009-02-24 5:43 ` Performance regression in write() syscall Salman Qazi
2009-02-24 10:09 ` Andi Kleen
2009-02-24 16:13 ` Ingo Molnar
2009-02-24 16:51 ` Andi Kleen
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=20090228173813.6d86c0ef@infradead.org \
--to=arjan@infradead.org \
--cc=andi@firstfloor.org \
--cc=davem@davemloft.net \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=nickpiggin@yahoo.com.au \
--cc=sqazi@google.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/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;
as well as URLs for NNTP newsgroup(s).