From: Peter Zijlstra <peterz@infradead.org>
To: Borislav Petkov <borislav.petkov@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Stephane Eranian <eranian@google.com>,
linux-kernel@vger.kernel.org, andi@firstfloor.org, mingo@elte.hu,
ming.m.lin@intel.com,
Andreas Herrmann <andreas.herrmann3@amd.com>,
Dimitri Sivanich <sivanich@sgi.com>,
Dmitry Adamushko <dmitry.adamushko@gmail.com>
Subject: Re: [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge
Date: Fri, 08 Jun 2012 16:20:50 +0200 [thread overview]
Message-ID: <1339165250.2507.27.camel@laptop> (raw)
In-Reply-To: <20120608141543.GD31359@aftab.osrc.amd.com>
On Fri, 2012-06-08 at 16:15 +0200, Borislav Petkov wrote:
> have a variable which gets initialized to the number of all CPUs and
> each time ->apply_microcode() finishes by returning 0, we decrement it
> once.
>
> Hmm, I'm probably missing some obscure case.
Since its all per-cpu sysfs muck, userspace could update a random
subsets of cpus.. leaving us hanging.
The 'bestestet' idea I came up with is doing the verify thing I have
from a delayed work -- say 1 second into the future. That way, when
there's lots of cpus they all try and enqueue the one work, which at the
end executes only once, provided the entire update scan took less than
the second.
But yuck..
next prev parent reply other threads:[~2012-06-08 14:21 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 [this message]
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
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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