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| author | Tim Blechmann <tim@klingt.org> | 2009-02-19 17:34:03 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-03 12:04:22 +0100 |
| commit | 780eef9492b16a1543a3b2ae9f9526a735fc9856 (patch) | |
| tree | d3c4942a98845558d45e4b36d5350ebf41cde524 | |
| parent | x86: fix init_memory_mapping() to handle small ranges (diff) | |
| download | linux-780eef9492b16a1543a3b2ae9f9526a735fc9856.tar.xz linux-780eef9492b16a1543a3b2ae9f9526a735fc9856.zip | |
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>
| -rw-r--r-- | 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 e9f80c744cf3..10131fbdaada 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 */ |