i386: do not BUG_ON() when MSR is unknown

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).

[watchdog] do not BUG_ON() in the MSR allocator if MSR is unknown, return ok
instead

Signed-off-by: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 54cdbf1a40f1a054bb5d9affc0c9c77fb913482b..c02541e6e653f72ae1856df090b0719041cd2664 100644 (file)
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/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 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;
 
        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 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;
 
        clear_bit(counter, evntsel_nmi_owner);
 }