From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>, Dave Jones <davej@redhat.com>,
Zachary Amsden <zach@vmware.com>, Pavel Machek <pavel@ucw.cz>,
Andrew Morton <akpm@osdl.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Zwane Mwaikambo <zwane@arm.linux.org.uk>,
Pratap Subrahmanyam <pratap@vmware.com>,
Christopher Li <chrisl@vmware.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Ingo Molnar <mingo@elte.hu>,
torvalds@osdl.org
Subject: Re: [PATCH 1/10] Cr4 is valid on some 486s
Date: Sun, 13 Nov 2005 11:56:46 -0800 [thread overview]
Message-ID: <43779A7E.7020201@zytor.com> (raw)
In-Reply-To: <1131902775.25311.16.camel@localhost.localdomain>
Alan Cox wrote:
> On Sul, 2005-11-13 at 11:59 +0100, Andi Kleen wrote:
>
>>Dave Jones <davej@redhat.com> writes:
>>
>>>Looks like the Ubuntu people already did this...
>>>
>>>http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-2.6.git;a=commitdiff;h=048985336e32efe665cddd348e92e4a4a5351415;hp=1cb630c2b5aaad7cedaa78aa135e6cecf5ab91ac
>>
>>It's probably not needed. At least AMD K7/K8 has a SYSCFG MSR bit to
>>do this (or rather they disable bus cycles for locks that makes them
>>very cheap) Intel has one too in a different MSR that looks similar.
>>With some luck they're even already set by the BIOS on UP systems. I
>>know they are on some AMD systems.
>
> I'd hope the vendors are not doing that by default because we have
> kernel code that uses lock against not other processors but other bus
> masters. The ECC code is one example. Is there any good info on the AMD
> one so I can make the EDAC code put the processor back in x86 compatible
> mode so that it behaves safely when scrubbing.
>
I can't speak about AMD, but on Transmeta's CPUs operations against
cached memory are *always* atomic; the atomicity is guaranteed by the
cache hierarchy. The LOCK prefix does have effects against uncached memory.
-hpa
next prev parent reply other threads:[~2005-11-13 19:57 UTC|newest]
Thread overview: 154+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-10 0:32 Zachary Amsden
2005-11-11 10:36 ` Pavel Machek
2005-11-11 17:49 ` H. Peter Anvin
2005-11-11 18:00 ` Maciej W. Rozycki
2005-11-11 19:36 ` Zachary Amsden
2005-11-11 19:58 ` Linus Torvalds
2005-11-11 20:14 ` Zachary Amsden
2005-11-11 20:22 ` Linus Torvalds
2005-11-13 7:42 ` Dave Jones
2005-11-13 10:59 ` Andi Kleen
2005-11-13 17:26 ` Alan Cox
2005-11-13 17:09 ` Eric W. Biederman
2005-11-13 19:00 ` Andi Kleen
2005-11-13 19:07 ` Eric W. Biederman
2005-11-13 19:41 ` Alan Cox
2005-11-13 19:36 ` Linus Torvalds
2005-11-13 21:32 ` Alan Cox
2005-11-14 7:46 ` Arjan van de Ven
2005-11-13 19:56 ` H. Peter Anvin [this message]
2005-11-13 19:24 ` Linus Torvalds
2005-11-13 20:29 ` Linus Torvalds
2005-11-14 15:06 ` Gerd Knorr
2005-11-14 19:25 ` Linus Torvalds
2005-11-14 19:46 ` Zachary Amsden
2005-11-14 19:52 ` Arjan van de Ven
2005-11-14 20:34 ` Zachary Amsden
2005-11-14 20:52 ` Arjan van de Ven
2005-11-15 14:12 ` Gerd Knorr
2005-11-15 16:01 ` Gerd Knorr
2005-11-15 16:04 ` Zachary Amsden
2005-11-15 16:06 ` Arjan van de Ven
2005-11-15 16:10 ` Dave Jones
2005-11-15 16:14 ` H. Peter Anvin
2005-11-15 16:19 ` Dave Jones
2005-11-15 16:25 ` Arjan van de Ven
2005-11-15 16:34 ` Zachary Amsden
2005-11-15 16:28 ` H. Peter Anvin
2005-11-15 16:24 ` Zachary Amsden
2005-11-15 16:52 ` Linus Torvalds
2005-11-15 16:16 ` Gerd Knorr
2005-11-15 16:08 ` Roland Dreier
2005-11-16 9:58 ` Gerd Knorr
2005-11-15 16:12 ` Linus Torvalds
2005-11-15 16:16 ` Dave Jones
2005-11-15 16:27 ` Gerd Knorr
2005-11-16 16:12 ` [RFC] SMP alternatives Gerd Knorr
2005-11-22 17:48 ` [patch] " Gerd Knorr
2005-11-22 18:01 ` Pavel Machek
2005-11-23 15:12 ` Vincent Hanquez
2005-11-23 19:17 ` Andi Kleen
2005-11-23 15:29 ` Gerd Knorr
2005-11-23 16:42 ` Alan Cox
2005-11-23 16:39 ` Andi Kleen
2005-11-23 17:21 ` Alan Cox
2005-11-23 16:59 ` Andi Kleen
2005-11-23 22:00 ` Alan Cox
2005-11-24 13:13 ` Andi Kleen
2005-11-24 13:30 ` Eric W. Biederman
2005-11-24 13:39 ` Andi Kleen
2005-11-24 13:58 ` Eric W. Biederman
2005-11-24 19:16 ` thockin
2005-11-24 19:26 ` Andi Kleen
2005-11-24 14:34 ` Alan Cox
2005-11-24 14:22 ` Andi Kleen
2005-11-24 15:15 ` Alan Cox
2005-11-24 14:55 ` Andi Kleen
2005-11-24 15:09 ` Eric W. Biederman
2005-11-24 15:36 ` Andi Kleen
2005-11-24 16:49 ` Eric W. Biederman
2005-11-24 19:12 ` thockin
2005-11-24 19:14 ` Andi Kleen
2005-11-24 19:24 ` thockin
2005-11-24 19:29 ` Andi Kleen
2005-11-24 19:44 ` thockin
2005-11-24 21:20 ` Andi Kleen
2005-11-24 21:40 ` thockin
2005-11-24 23:33 ` Eric W. Biederman
2005-11-24 23:12 ` Alan Cox
2005-11-24 22:48 ` thockin
2005-11-24 23:35 ` Andi Kleen
2005-11-25 0:13 ` Alan Cox
2005-11-25 1:33 ` H. Peter Anvin
2005-11-28 19:15 ` Bill Davidsen
2005-11-24 16:02 ` Alan Cox
2005-11-24 19:09 ` thockin
2005-11-24 14:30 ` Alan Cox
2005-11-23 17:02 ` Linus Torvalds
2005-11-23 18:02 ` H. Peter Anvin
2005-11-23 18:42 ` Linus Torvalds
2005-11-23 17:26 ` Jeff V. Merkey
2005-11-23 19:03 ` Linus Torvalds
2005-11-23 19:31 ` jmerkey
2005-11-23 18:46 ` Andi Kleen
2005-11-23 19:12 ` H. Peter Anvin
2005-11-23 19:30 ` jmerkey
2005-11-23 21:44 ` Alan Cox
2005-11-23 21:13 ` Andi Kleen
2005-11-23 21:46 ` Jeff Garzik
2005-11-23 22:23 ` Andi Kleen
2005-11-23 22:30 ` Pavel Machek
2005-11-23 22:05 ` Alan Cox
2005-11-23 21:36 ` Arjan van de Ven
2005-11-23 21:36 ` Andi Kleen
2005-11-23 22:13 ` Linus Torvalds
2005-11-23 21:36 ` Linus Torvalds
2005-11-23 21:43 ` Andi Kleen
2005-11-23 22:15 ` Linus Torvalds
2005-11-23 22:22 ` Andi Kleen
2005-11-23 22:25 ` H. Peter Anvin
2005-11-23 22:32 ` Andi Kleen
2005-11-23 22:36 ` H. Peter Anvin
2005-11-23 22:40 ` Andi Kleen
2005-11-23 22:52 ` H. Peter Anvin
2005-11-23 23:10 ` Linus Torvalds
2005-11-24 0:55 ` Jeff Garzik
2005-11-23 21:48 ` Daniel Jacobowitz
2005-11-23 21:53 ` H. Peter Anvin
2005-11-23 22:03 ` Daniel Jacobowitz
2005-11-23 22:09 ` H. Peter Anvin
2005-11-23 22:21 ` Linus Torvalds
2005-11-23 23:29 ` Eric W. Biederman
2005-11-23 23:40 ` Linus Torvalds
2005-11-23 22:19 ` Linus Torvalds
2005-11-23 22:20 ` Daniel Jacobowitz
2005-11-23 23:08 ` Linus Torvalds
2005-11-23 23:02 ` Jeff V. Merkey
2005-11-23 23:42 ` Daniel Jacobowitz
2005-11-23 23:59 ` Linus Torvalds
2005-11-24 2:06 ` Daniel Jacobowitz
2005-11-24 22:32 ` Ulrich Drepper
2005-11-28 19:58 ` Bill Davidsen
2005-11-24 1:02 ` Jeff Garzik
2005-11-24 13:01 ` Pádraig Brady
2005-11-24 13:12 ` Arjan van de Ven
2005-11-28 19:52 ` Bill Davidsen
2005-11-28 20:05 ` Zachary Amsden
2005-11-28 22:19 ` Jeff V. Merkey
2005-11-28 23:00 ` Zachary Amsden
2005-11-28 23:07 ` H. Peter Anvin
2005-11-28 23:30 ` Zachary Amsden
2005-11-28 23:32 ` H. Peter Anvin
2005-11-28 23:12 ` Andi Kleen
2005-11-23 22:50 ` Alan Cox
2005-11-23 22:22 ` H. Peter Anvin
2005-11-25 7:38 ` Chris Wedgwood
2005-11-25 17:33 ` Linus Torvalds
2005-11-28 20:25 ` Bill Davidsen
2005-11-25 20:13 ` H. Peter Anvin
2005-11-24 3:23 ` Mikulas Patocka
2005-11-24 3:31 ` Mikulas Patocka
2005-11-24 3:55 ` H. Peter Anvin
2005-11-24 22:30 ` Ulrich Drepper
2005-11-23 16:43 ` Gerd Knorr
2005-11-23 16:51 ` H. Peter Anvin
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