From: Bill Davidsen <davidsen@tmr.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: richard.brunner@amd.com, alan@lxorguk.ukuu.org.uk,
zwane@linuxpower.ca, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata
Date: Thu, 18 Sep 2003 13:34:04 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.3.96.1030918130129.7139D-100000@gatekeeper.tmr.com> (raw)
In-Reply-To: <20030918074331.GA386@elf.ucw.cz>
On Thu, 18 Sep 2003, Pavel Machek wrote:
> > I think Alan brought up a very good point. Even if you
> > use a generic kernel that avoids prefetch use on Athlon
> > (which I am opposed to), it doesn't solve the problem
> > of user space programs detecting that the ISA supports
> > prefetch and using prefetch instructions and hitting the
> > errata on Athlon.
> >
> > The user space problem worries me more, because the expectation
> > is that if CPUID says the program can use perfetch, it could
> > and should regardless of what the kernel decided to do here.
>
> User programs should not rely on cpuid; they should read /proc/cpuinfo
> exactly because this kind of errata.
That's fine, but impacts portability. I don't think there is a right
way, since the o/s may not know about some features and the CPU may be
optimistic. Unless they are "recent Linux only" programs they may well
check the CPU itself, there are reasons for it in portable code.
--
bill davidsen <davidsen@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.
next prev parent reply other threads:[~2003-09-18 17:43 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-15 16:21 [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata richard.brunner
2003-09-15 19:15 ` Bill Davidsen
2003-09-16 11:46 ` Jamie Lokier
2003-09-16 13:30 ` Dave Jones
2003-09-16 13:52 ` Bill Davidsen
2003-09-16 15:25 ` Timothy Miller
2003-09-16 16:53 ` Bill Davidsen
2003-09-16 17:22 ` Jamie Lokier
2003-09-16 17:23 ` Jamie Lokier
2003-09-18 7:43 ` Pavel Machek
2003-09-18 14:05 ` Dave Jones
2003-09-18 15:56 ` Jamie Lokier
2003-09-18 17:34 ` Bill Davidsen [this message]
-- strict thread matches above, loose matches on Subject: below --
2003-09-16 2:23 richard.brunner
2003-09-15 20:20 Nakajima, Jun
2003-09-15 20:03 Nakajima, Jun
2003-09-15 19:51 richard.brunner
2003-09-16 0:01 ` David Lang
2003-09-16 0:20 ` Bill Davidsen
2003-09-16 11:50 ` Jamie Lokier
2003-09-16 13:46 ` Bill Davidsen
2003-09-16 17:21 ` Jamie Lokier
2003-09-15 19:34 John Bradford
2003-09-15 19:25 ` Bill Davidsen
2003-09-15 22:28 ` Alan Cox
2003-09-15 19:19 John Bradford
[not found] <200309150632.h8F6WnHb000589@81-2-122-30.bradfords.org.uk.suse.lists.linux.kernel>
[not found] ` <1063611650.2674.1.camel@dhcp23.swansea.linux.org.uk.suse.lists.linux.kernel>
2003-09-15 18:29 ` Andi Kleen
2003-09-15 14:21 John Bradford
2003-09-15 12:43 John Bradford
2003-09-15 18:21 ` Bill Davidsen
2003-09-15 12:28 Mikael Pettersson
2003-09-15 18:13 ` Bill Davidsen
2003-09-16 11:54 ` Jamie Lokier
2003-09-15 11:46 John Bradford
2003-09-15 12:38 ` Nick Piggin
2003-09-15 13:46 ` Chris Meadors
2003-09-15 14:00 ` Nick Piggin
2003-09-16 15:06 ` Bill Davidsen
2003-09-16 15:24 ` Nick Piggin
2003-09-15 10:54 John Bradford
2003-09-15 10:52 ` Nick Piggin
2003-09-15 13:45 ` Alan Cox
2003-09-15 18:44 ` Bill Davidsen
2003-09-15 9:39 John Bradford
2003-09-15 9:58 ` Nick Piggin
2003-09-15 8:31 John Bradford
2003-09-15 8:32 ` Nick Piggin
2003-09-15 20:51 ` Adrian Bunk
2003-09-15 6:32 John Bradford
2003-09-15 7:40 ` Alan Cox
2003-09-15 12:02 ` Bill Davidsen
2003-09-15 11:48 ` Bill Davidsen
2003-09-15 20:55 ` Adrian Bunk
2003-09-16 0:26 ` Bill Davidsen
2003-09-12 21:24 John Bradford
2003-09-11 17:17 richard.brunner
2003-09-13 16:54 ` Pavel Machek
2003-09-11 17:14 richard.brunner
2003-09-11 17:09 richard.brunner
2003-09-11 4:55 richard.brunner
2003-09-11 16:55 ` Jamie Lokier
2003-09-12 14:14 ` Martin Schlemmer
[not found] <uqD5.3BI.3@gated-at.bofh.it>
2003-09-11 4:14 ` Andi Kleen
2003-09-11 4:58 ` dada1
2003-09-11 5:11 ` Andi Kleen
2003-09-11 5:58 ` dada1
2003-09-11 3:43 Nakajima, Jun
2003-09-11 4:03 ` Valdis.Kletnieks
2003-09-11 0:56 Update on AMD Athlon/Opteron/Athlon64 Prefetch Errata richard.brunner
2003-09-11 1:27 ` [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata Andi Kleen
2003-09-11 1:44 ` Andrew Morton
2003-09-11 1:47 ` Andi Kleen
2003-09-11 14:15 ` Jeff Garzik
2003-09-11 14:26 ` Andi Kleen
2003-09-11 14:34 ` Jeff Garzik
2003-09-11 14:58 ` Andi Kleen
2003-09-11 15:06 ` Jeff Garzik
2003-09-11 20:08 ` bill davidsen
2003-09-11 19:56 ` bill davidsen
2003-09-11 20:44 ` Alan Cox
2003-09-11 21:29 ` Mike Fedyk
2003-09-11 21:38 ` bill davidsen
2003-09-12 17:32 ` Eric W. Biederman
2003-09-12 17:56 ` Andi Kleen
2003-09-12 17:59 ` Jeff Garzik
2003-09-12 18:22 ` Adrian Bunk
2003-09-12 18:28 ` Andi Kleen
2003-09-12 18:39 ` Jeff Garzik
2003-09-12 18:45 ` Jeff Garzik
2003-09-12 18:48 ` Adrian Bunk
2003-09-12 19:07 ` Andi Kleen
2003-09-12 19:05 ` Martin Schlemmer
2003-09-12 19:30 ` Andi Kleen
2003-09-12 19:58 ` Martin Schlemmer
2003-09-12 20:00 ` Adrian Bunk
2003-09-15 0:15 ` bill davidsen
2003-09-14 23:51 ` bill davidsen
2003-09-14 23:49 ` bill davidsen
2003-09-14 23:47 ` bill davidsen
2003-09-15 1:02 ` Zwane Mwaikambo
2003-09-15 2:08 ` Nick Piggin
2003-09-15 3:55 ` Bill Davidsen
2003-09-15 7:45 ` Alan Cox
2003-09-15 12:11 ` Bill Davidsen
2003-09-15 13:48 ` Alan Cox
2003-09-15 18:50 ` Bill Davidsen
2003-09-12 18:03 ` Mike Fedyk
2003-09-11 13:54 ` Linus Torvalds
2003-09-11 14:01 ` Andi Kleen
2003-09-11 14:14 ` Dave Jones
2003-09-11 14:29 ` Andi Kleen
2003-09-11 14:14 ` Alan Cox
2003-09-11 14:24 ` Andi Kleen
2003-09-11 14:28 ` Dave Jones
2003-09-11 14:32 ` Andi Kleen
2003-09-11 20:14 ` bill davidsen
2003-09-11 16:58 ` Jamie Lokier
2003-09-11 17:05 ` Andi Kleen
2003-09-11 17:32 ` Jamie Lokier
2003-09-11 17:39 ` Andi Kleen
2003-09-11 17:48 ` Jamie Lokier
2003-09-11 18:18 ` Andi Kleen
2003-09-11 18:59 ` Jamie Lokier
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