From: Peter Zijlstra <peterz@infradead.org>
To: Borislav Petkov <bp@amd64.org>
Cc: LKML <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>,
Andreas Herrmann <andreas.herrmann3@amd.com>,
Dimitri Sivanich <sivanich@sgi.com>,
Dmitry Adamushko <dmitry.adamushko@gmail.com>,
Greg Kroah-Hartman <greg@kroah.com>
Subject: Re: [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge
Date: Fri, 15 Jun 2012 14:42:41 +0200 [thread overview]
Message-ID: <1339764161.2559.63.camel@twins> (raw)
In-Reply-To: <20120615123749.GC6083@aftab.osrc.amd.com>
On Fri, 2012-06-15 at 14:37 +0200, Borislav Petkov wrote:
> This is a minimal fix which we'd like to see in stable too thus the
> more-or-less arbitrary decision to allow system-wide reloading only on
> the BSP:
>
> $ echo 1 > /sys/devices/system/cpu/cpu0/microcode/reload
> ...
>
> and disable the interface on the other cores:
>
> $ echo 1 > /sys/devices/system/cpu/cpu23/microcode/reload
> -bash: echo: write error: Invalid argument
One could allow the reload from all cpus and simply do all cpus, but I
guess the rationale for not doing that and restricting it to cpu0 is to
avoid the O(n^2) thing in case userspace issues a reload on all cpus?
If so it would be good to mention in the Changelog so people see its not
a 'random' choice.
next prev parent reply other threads:[~2012-06-15 12:42 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 [this message]
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
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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