From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@amd64.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Stephane Eranian <eranian@google.com>,
linux-kernel@vger.kernel.org, andi@firstfloor.org, mingo@elte.hu,
ming.m.lin@intel.com, "Yu, Fenghua" <fenghua.yu@intel.com>
Subject: Re: [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge
Date: Tue, 12 Jun 2012 13:58:23 -0700 [thread overview]
Message-ID: <4FD7AD6F.6010008@zytor.com> (raw)
In-Reply-To: <20120612205609.GF11137@aftab.osrc.amd.com>
On 06/12/2012 01:56 PM, Borislav Petkov wrote:
> On Tue, Jun 12, 2012 at 01:42:07PM -0700, H. Peter Anvin wrote:
>> I personally don't know of any valid use case for per-core loads, and
>> it sounds like a horrid idea.
>
> Vehemently agreed.
>
> However, last time we talked about Ingo mentioned some possibility
> of having different microcode versions on different CPUs:
> http://lkml.indiana.edu/hypermail/linux/kernel/1105.3/00749.html
>
> Hmm...
>
>> And yes, I would prefer a single sysfs file, or better yet a plain old
>> device node.
>
> Also agreed.
>
There is a difference here. Mixed steppings or even mixed CPUs are,
indeed, supported (even things like Nehalem + Westmere in the same
system). However, the notion is that we should upload the *entire set*
of microcodes to the kernel, and let it flash the appropriate one into
each CPU.
This may result in different version number on different CPUs.
-hpa
next prev parent reply other threads:[~2012-06-12 20:58 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-07 7:15 [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge Stephane Eranian
2012-06-07 10:18 ` Peter Zijlstra
2012-06-07 10:35 ` Stephane Eranian
2012-06-07 10:45 ` Peter Zijlstra
2012-06-07 10:48 ` Stephane Eranian
2012-06-07 11:15 ` Peter Zijlstra
2012-06-08 9:35 ` Ingo Molnar
2012-06-08 10:00 ` Peter Zijlstra
2012-06-08 10:03 ` Stephane Eranian
2012-06-08 13:26 ` Peter Zijlstra
2012-06-08 13:51 ` Borislav Petkov
2012-06-08 13:54 ` Peter Zijlstra
2012-06-08 14:15 ` Borislav Petkov
2012-06-08 14:20 ` Peter Zijlstra
2012-06-08 14:36 ` Borislav Petkov
2012-06-08 14:45 ` Peter Zijlstra
2012-06-08 15:09 ` Borislav Petkov
2012-06-08 13:56 ` Peter Zijlstra
2012-06-08 14:03 ` Borislav Petkov
2012-06-08 13:59 ` Peter Zijlstra
2012-06-08 14:03 ` Stephane Eranian
2012-06-08 14:17 ` Borislav Petkov
2012-06-08 16:02 ` H. Peter Anvin
2012-06-08 21:02 ` Henrique de Moraes Holschuh
2012-06-08 21:16 ` Borislav Petkov
2012-06-08 14:07 ` Stephane Eranian
2012-06-08 14:13 ` Peter Zijlstra
2012-06-08 14:19 ` Borislav Petkov
2012-06-08 14:23 ` Peter Zijlstra
2012-06-08 14:26 ` Stephane Eranian
2012-06-08 14:25 ` Peter Zijlstra
2012-06-08 14:26 ` Stephane Eranian
2012-06-12 8:14 ` Stephane Eranian
2012-06-08 16:28 ` Stephane Eranian
2012-06-08 18:49 ` Peter Zijlstra
2012-06-08 16:50 ` Andi Kleen
2012-06-08 18:05 ` Borislav Petkov
2012-06-08 18:52 ` Peter Zijlstra
2012-06-08 20:38 ` Borislav Petkov
2012-06-12 17:07 ` Robert Richter
2012-06-12 17:09 ` Stephane Eranian
2012-06-12 17:13 ` Peter Zijlstra
2012-06-12 17:17 ` Borislav Petkov
2012-06-12 17:18 ` Peter Zijlstra
2012-06-12 17:23 ` Borislav Petkov
2012-06-12 17:26 ` Peter Zijlstra
2012-06-12 17:35 ` Borislav Petkov
2012-06-12 17:40 ` Peter Zijlstra
2012-06-12 18:04 ` Andi Kleen
2012-06-12 20:10 ` Borislav Petkov
2012-06-13 1:04 ` Henrique de Moraes Holschuh
2012-06-13 6:51 ` Borislav Petkov
2012-06-13 12:36 ` Henrique de Moraes Holschuh
2012-06-13 16:11 ` Borislav Petkov
2012-06-13 21:41 ` Henrique de Moraes Holschuh
2012-06-15 12:37 ` Borislav Petkov
2012-06-15 12:42 ` Peter Zijlstra
2012-06-15 12:52 ` Borislav Petkov
2012-06-15 16:52 ` [PATCH] x86, microcode: Make reload interface per system Borislav Petkov
2012-06-15 17:16 ` Peter Zijlstra
2012-06-15 17:49 ` Borislav Petkov
2012-06-19 2:46 ` Henrique de Moraes Holschuh
2012-06-19 3:31 ` H. Peter Anvin
2012-06-19 5:11 ` Borislav Petkov
2012-06-19 8:17 ` Peter Zijlstra
2012-06-19 10:22 ` Borislav Petkov
2012-06-19 10:26 ` Peter Zijlstra
2012-06-19 15:06 ` Borislav Petkov
2012-06-19 15:57 ` H. Peter Anvin
2012-06-19 18:22 ` Henrique de Moraes Holschuh
2012-06-19 20:22 ` H. Peter Anvin
2012-06-20 23:46 ` Henrique de Moraes Holschuh
2012-06-20 23:49 ` H. Peter Anvin
2012-06-21 0:06 ` Henrique de Moraes Holschuh
2012-06-21 0:18 ` H. Peter Anvin
2012-06-21 2:33 ` Henrique de Moraes Holschuh
2012-06-19 5:03 ` Borislav Petkov
2012-06-19 18:57 ` Henrique de Moraes Holschuh
2012-06-19 22:19 ` Borislav Petkov
2012-06-19 2:42 ` [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge Henrique de Moraes Holschuh
2012-06-12 17:23 ` Robert Richter
2012-06-12 17:15 ` Borislav Petkov
2012-06-07 13:28 ` Andi Kleen
2012-06-07 13:27 ` Andi Kleen
2012-06-12 18:35 ` H. Peter Anvin
2012-06-12 19:07 ` Borislav Petkov
2012-06-12 19:33 ` Peter Zijlstra
2012-06-12 19:35 ` Andi Kleen
2012-06-12 19:49 ` Borislav Petkov
2012-06-12 20:28 ` H. Peter Anvin
2012-06-12 20:37 ` Borislav Petkov
2012-06-12 20:42 ` H. Peter Anvin
2012-06-12 20:56 ` Borislav Petkov
2012-06-12 20:58 ` H. Peter Anvin [this message]
2012-06-12 21:04 ` Borislav Petkov
2012-06-13 8:38 ` Peter Zijlstra
2012-06-13 14:00 ` H. Peter Anvin
2012-06-13 15:37 ` Peter Zijlstra
2012-06-13 15:46 ` H. Peter Anvin
2012-06-13 12:39 ` Peter Zijlstra
2012-06-13 13:22 ` H. Peter Anvin
2012-06-13 14:01 ` Henrique de Moraes Holschuh
2012-06-13 8:32 ` Peter Zijlstra
2012-06-13 13:59 ` H. Peter Anvin
2012-06-13 15:32 ` Peter Zijlstra
2012-06-13 15:38 ` H. Peter Anvin
2012-06-12 20:27 ` H. Peter Anvin
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