From: Stephane Eranian Here is a small patch to change the behavior of the PMU msr allocator to avoid BUG_ON() when the MSR is unknwon. Instead, it now returns ok, which means "I do not manage". The current allocator is not yet managing the full set of PMU registers (e.g., GLOBAL_* on Core 2). Signed-off-by: Stephane Eranian Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/kernel/cpu/perfctr-watchdog.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff -puN arch/i386/kernel/cpu/perfctr-watchdog.c~perfctr_watchdog-do-not-bug_on-when-msr-is-unknown arch/i386/kernel/cpu/perfctr-watchdog.c --- a/arch/i386/kernel/cpu/perfctr-watchdog.c~perfctr_watchdog-do-not-bug_on-when-msr-is-unknown +++ a/arch/i386/kernel/cpu/perfctr-watchdog.c @@ -120,7 +120,9 @@ int reserve_perfctr_nmi(unsigned int msr unsigned int counter; counter = nmi_perfctr_msr_to_bit(msr); - BUG_ON(counter > NMI_MAX_COUNTER_BITS); + /* register not managed by the allocator? */ + if (counter > NMI_MAX_COUNTER_BITS) + return 1; if (!test_and_set_bit(counter, perfctr_nmi_owner)) return 1; @@ -132,7 +134,9 @@ void release_perfctr_nmi(unsigned int ms unsigned int counter; counter = nmi_perfctr_msr_to_bit(msr); - BUG_ON(counter > NMI_MAX_COUNTER_BITS); + /* register not managed by the allocator? */ + if (counter > NMI_MAX_COUNTER_BITS) + return; clear_bit(counter, perfctr_nmi_owner); } @@ -142,7 +146,9 @@ int reserve_evntsel_nmi(unsigned int msr unsigned int counter; counter = nmi_evntsel_msr_to_bit(msr); - BUG_ON(counter > NMI_MAX_COUNTER_BITS); + /* register not managed by the allocator? */ + if (counter > NMI_MAX_COUNTER_BITS) + return 1; if (!test_and_set_bit(counter, evntsel_nmi_owner)) return 1; @@ -154,7 +160,9 @@ void release_evntsel_nmi(unsigned int ms unsigned int counter; counter = nmi_evntsel_msr_to_bit(msr); - BUG_ON(counter > NMI_MAX_COUNTER_BITS); + /* register not managed by the allocator? */ + if (counter > NMI_MAX_COUNTER_BITS) + return; clear_bit(counter, evntsel_nmi_owner); } _