From: Andrew Morton <akpm@osdl.org>
To: Nick Piggin <piggin@cyberone.com.au>
Cc: ak@suse.de, torvalds@osdl.org, linux-kernel@vger.kernel.org,
richard.brunner@amd.com
Subject: Re: [PATCH] Athlon/Opteron Prefetch Fix for 2.6.0test5 + numbers
Date: Tue, 16 Sep 2003 22:08:43 -0700 [thread overview]
Message-ID: <20030916220843.31533480.akpm@osdl.org> (raw)
In-Reply-To: <3F67E8D4.6010707@cyberone.com.au>
Nick Piggin <piggin@cyberone.com.au> wrote:
>
> What is intriguing to me is the "Its only a 2% slowdown of the page
> fault for every cpu other than K[78] for this single workaround. There
> is no point to conditional compilation" attitude some people have.
> Of course, its only 2% on a pagefault, not anywhere near 2% of kernel
> performance as a whole, so maybe that is justified.
Absolutely. But it's a bit of a pain finding a config option which says
"this CPU might need the fixup".
> Just repeating though, that is a seperate issue and I think Andi's patch
> is needed.
It is unquestionably needed - the kernel _has_ to perform the fixup for this
CPU erratum.
But I would like to see some evidence that prefetch ever provides any
performance gain in-kernel. I spent some time fiddling a while back and
was unable to demonstrate any difference.
next prev parent reply other threads:[~2003-09-17 5:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-17 2:22 [PATCH] Athlon/Opteron Prefetch Fix for 2.6.0test5 + numbers Andi Kleen
2003-09-17 2:44 ` Andrew Morton
2003-09-17 3:25 ` Andi Kleen
2003-09-17 4:53 ` Nick Piggin
2003-09-17 5:08 ` Andrew Morton [this message]
2003-09-17 5:19 ` Nick Piggin
2003-09-17 7:15 ` Dave Hansen
2003-09-17 5:26 ` Andi Kleen
2003-09-17 5:44 ` Nick Piggin
2003-09-17 19:53 ` Linus Torvalds
2003-09-17 20:21 ` Andi Kleen
2003-09-17 20:50 ` Linus Torvalds
2003-09-17 21:12 ` Andi Kleen
2003-09-18 15:38 ` Jamie Lokier
2003-09-18 16:04 ` Jamie Lokier
2003-09-18 17:06 ` Andi Kleen
2003-09-18 19:48 ` Jamie Lokier
2003-09-19 6:55 ` Kai Henningsen
2003-09-19 10:02 ` Andreas Schwab
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=20030916220843.31533480.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=ak@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=piggin@cyberone.com.au \
--cc=richard.brunner@amd.com \
--cc=torvalds@osdl.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