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authorRobert Richter <robert.richter@amd.com>2009-06-12 17:58:48 +0200
committerRobert Richter <robert.richter@amd.com>2009-06-12 17:58:48 +0200
commit1241eb8f136bf3ea409f61590e7663465906d158 (patch)
treec8384237f19bb1094d9c90825a74e28393b60d00 /arch/x86/oprofile/op_model_ppro.c
parent51563a0e5650d0d76539625388d72d62b34c726e (diff)
parent940010c5a314a7bd9b498593bc6ba1718ac5aec5 (diff)
Merge commit 'tip/perfcounters-for-linus' into oprofile/master
Conflicts: arch/x86/oprofile/op_model_ppro.c Signed-off-by: Robert Richter <robert.richter@amd.com>
Diffstat (limited to 'arch/x86/oprofile/op_model_ppro.c')
-rw-r--r--arch/x86/oprofile/op_model_ppro.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c
index 0a261a5c696e..cd72d5c73b49 100644
--- a/arch/x86/oprofile/op_model_ppro.c
+++ b/arch/x86/oprofile/op_model_ppro.c
@@ -118,6 +118,13 @@ static int ppro_check_ctrs(struct pt_regs * const regs,
u64 val;
int i;
+ /*
+ * This can happen if perf counters are in use when
+ * we steal the die notifier NMI.
+ */
+ if (unlikely(!reset_value))
+ goto out;
+
for (i = 0 ; i < num_counters; ++i) {
if (!reset_value[i])
continue;
@@ -128,6 +135,7 @@ static int ppro_check_ctrs(struct pt_regs * const regs,
wrmsrl(msrs->counters[i].addr, -reset_value[i]);
}
+out:
/* Only P6 based Pentium M need to re-unmask the apic vector but it
* doesn't hurt other P6 variant */
apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);