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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-04-06 11:45:03 +0200
committerIngo Molnar <mingo@elte.hu>2009-04-07 10:48:56 +0200
commitb6276f353bf490add62dcf7db0ebd75baa3e1a37 (patch)
tree9720a848fca77555bef9658c56445815f6f2a29d /arch/x86/kernel
parent671dec5daf3b3c43c5777be282f00120a44cf37f (diff)
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>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/cpu/perf_counter.c14
-rw-r--r--arch/x86/kernel/entry_64.S2
-rw-r--r--arch/x86/kernel/irq.c5
-rw-r--r--arch/x86/kernel/irqinit_32.c1
-rw-r--r--arch/x86/kernel/irqinit_64.c1
5 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index c74e20d593a..438415866fe 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -849,6 +849,20 @@ void smp_perf_counter_interrupt(struct pt_regs *regs)
irq_exit();
}
+void smp_perf_pending_interrupt(struct pt_regs *regs)
+{
+ irq_enter();
+ ack_APIC_irq();
+ inc_irq_stat(apic_pending_irqs);
+ perf_counter_do_pending();
+ irq_exit();
+}
+
+void set_perf_counter_pending(void)
+{
+ apic->send_IPI_self(LOCAL_PENDING_VECTOR);
+}
+
void perf_counters_lapic_init(int nmi)
{
u32 apic_val;
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 3f129d963a0..1d46cba56fd 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1028,6 +1028,8 @@ apicinterrupt SPURIOUS_APIC_VECTOR \
#ifdef CONFIG_PERF_COUNTERS
apicinterrupt LOCAL_PERF_VECTOR \
perf_counter_interrupt smp_perf_counter_interrupt
+apicinterrupt LOCAL_PENDING_VECTOR \
+ perf_pending_interrupt smp_perf_pending_interrupt
#endif
/*
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 9c2754302ec..d465487da58 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -67,6 +67,10 @@ static int show_other_interrupts(struct seq_file *p, int prec)
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 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
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;
diff --git a/arch/x86/kernel/irqinit_32.c b/arch/x86/kernel/irqinit_32.c
index 925d87cfc55..3190a6b961e 100644
--- a/arch/x86/kernel/irqinit_32.c
+++ b/arch/x86/kernel/irqinit_32.c
@@ -166,6 +166,7 @@ static void __init apic_intr_init(void)
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
# ifdef CONFIG_PERF_COUNTERS
alloc_intr_gate(LOCAL_PERF_VECTOR, perf_counter_interrupt);
+ alloc_intr_gate(LOCAL_PENDING_VECTOR, perf_pending_interrupt);
# endif
# ifdef CONFIG_X86_MCE_P4THERMAL
diff --git a/arch/x86/kernel/irqinit_64.c b/arch/x86/kernel/irqinit_64.c
index 665e2ab48ab..53ceb26f80f 100644
--- a/arch/x86/kernel/irqinit_64.c
+++ b/arch/x86/kernel/irqinit_64.c
@@ -156,6 +156,7 @@ static void __init apic_intr_init(void)
/* Performance monitoring interrupt: */
#ifdef CONFIG_PERF_COUNTERS
alloc_intr_gate(LOCAL_PERF_VECTOR, perf_counter_interrupt);
+ alloc_intr_gate(LOCAL_PENDING_VECTOR, perf_pending_interrupt);
#endif
}