perf_counter: x86: self-IPI for pending work
Implement set_perf_counter_pending() with a self-IPI so that it will
run ASAP in a usable context.
For now use a second IRQ vector, because the primary vector pokes
the apic in funny ways that seem to confuse things.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.724626696@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index c2e6bed..fe24d28 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -50,6 +50,7 @@
#ifdef CONFIG_PERF_COUNTERS
BUILD_INTERRUPT(perf_counter_interrupt, LOCAL_PERF_VECTOR)
+BUILD_INTERRUPT(perf_pending_interrupt, LOCAL_PENDING_VECTOR)
#endif
#ifdef CONFIG_X86_MCE_P4THERMAL
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 2545442..f5ebe2a 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -14,6 +14,7 @@
#endif
unsigned int generic_irqs; /* arch dependent */
unsigned int apic_perf_irqs;
+ unsigned int apic_pending_irqs;
#ifdef CONFIG_SMP
unsigned int irq_resched_count;
unsigned int irq_call_count;
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index ae80f64..7309c0ad 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -30,6 +30,7 @@
extern void generic_interrupt(void);
extern void error_interrupt(void);
extern void perf_counter_interrupt(void);
+extern void perf_pending_interrupt(void);
extern void spurious_interrupt(void);
extern void thermal_interrupt(void);
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 3cbd79b..545bb81 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -117,6 +117,11 @@
#define GENERIC_INTERRUPT_VECTOR 0xed
/*
+ * Performance monitoring pending work vector:
+ */
+#define LOCAL_PENDING_VECTOR 0xec
+
+/*
* First APIC vector available to drivers: (vectors 0x30-0xee) we
* start at 0x31(0x41) to spread out vectors evenly between priority
* levels. (0x80 is the syscall vector)
diff --git a/arch/x86/include/asm/perf_counter.h b/arch/x86/include/asm/perf_counter.h
index e2b0e66..d08dd52 100644
--- a/arch/x86/include/asm/perf_counter.h
+++ b/arch/x86/include/asm/perf_counter.h
@@ -84,7 +84,8 @@
#define MSR_ARCH_PERFMON_FIXED_CTR2 0x30b
#define X86_PMC_IDX_FIXED_BUS_CYCLES (X86_PMC_IDX_FIXED + 2)
-#define set_perf_counter_pending() do { } while (0)
+extern void set_perf_counter_pending(void);
+
#define clear_perf_counter_pending() do { } while (0)
#define test_perf_counter_pending() (0)