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/kernel/irq.c b/arch/x86/kernel/irq.c
index 9c27543..d465487 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -67,6 +67,10 @@
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
seq_printf(p, " Performance counter interrupts\n");
+ seq_printf(p, "PND: ");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->apic_pending_irqs);
+ seq_printf(p, " Performance pending work\n");
#endif
if (generic_interrupt_extension) {
seq_printf(p, "PLT: ");
@@ -171,6 +175,7 @@
sum += irq_stats(cpu)->apic_timer_irqs;
sum += irq_stats(cpu)->irq_spurious_count;
sum += irq_stats(cpu)->apic_perf_irqs;
+ sum += irq_stats(cpu)->apic_pending_irqs;
#endif
if (generic_interrupt_extension)
sum += irq_stats(cpu)->generic_irqs;