Messages in this thread Patch in this message | | | Date | Tue, 3 Mar 2009 21:45:05 +0100 | From | Ingo Molnar <> | Subject | Re: [Bug #12395] 2.6.28-rc9: oprofile regression |
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* Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Tuesday 03 March 2009, Robert Richter wrote: > > Fix upstream in tip/x86/urgent: > > > > 780eef9492b16a1543a3b2ae9f9526a735fc9856 > > URL, please?
The fix is not yet in Linus's tree - the commit is below.
Ingo
------------> From 780eef9492b16a1543a3b2ae9f9526a735fc9856 Mon Sep 17 00:00:00 2001 From: Tim Blechmann <tim@klingt.org> Date: Thu, 19 Feb 2009 17:34:03 +0100 Subject: [PATCH] x86: oprofile: don't set counter width from cpuid on Core2
Impact: fix stuck NMIs and non-working oprofile on certain CPUs
Resetting the counter width of the performance counters on Intel's Core2 CPUs, breaks the delivery of NMIs, when running in x86_64 mode.
This should fix bug #12395:
http://bugzilla.kernel.org/show_bug.cgi?id=12395
Signed-off-by: Tim Blechmann <tim@klingt.org> Signed-off-by: Robert Richter <robert.richter@amd.com> LKML-Reference: <20090303100412.GC10085@erda.amd.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- arch/x86/oprofile/op_model_ppro.c | 14 ++++++++++++-- 1 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c index e9f80c7..10131fb 100644 --- a/arch/x86/oprofile/op_model_ppro.c +++ b/arch/x86/oprofile/op_model_ppro.c @@ -78,8 +78,18 @@ static void ppro_setup_ctrs(struct op_msrs const * const msrs) if (cpu_has_arch_perfmon) { union cpuid10_eax eax; eax.full = cpuid_eax(0xa); - if (counter_width < eax.split.bit_width) - counter_width = eax.split.bit_width; + + /* + * For Core2 (family 6, model 15), don't reset the + * counter width: + */ + if (!(eax.split.version_id == 0 && + current_cpu_data.x86 == 6 && + current_cpu_data.x86_model == 15)) { + + if (counter_width < eax.split.bit_width) + counter_width = eax.split.bit_width; + } } /* clear all counters */
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