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perf_counter: x86: Remove interrupt throttle 

remove the x86 specific interrupt throttle

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.616671838@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Peter Zijlstra 2009-05-25 17:39:04 +02:00 committed by Ingo Molnar
parent ff99be573e
commit 48e22d56ec
3 changed files with 5 additions and 46 deletions
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2
arch/x86/kernel/apic/apic.c
View File

@ -763,8 +763,6 @@ static void local_apic_timer_interrupt(void)
inc_irq_stat(apic_timer_irqs);
evt->event_handler(evt);
perf_counter_unthrottle();
}
/*

47
arch/x86/kernel/cpu/perf_counter.c
View File

@ -718,11 +718,6 @@ static void intel_pmu_save_and_restart(struct perf_counter *counter)
intel_pmu_enable_counter(hwc, idx);
}
/*
* Maximum interrupt frequency of 100KHz per CPU
*/
#define PERFMON_MAX_INTERRUPTS (100000/HZ)
/*
* This handler is triggered by the local APIC, so the APIC IRQ handling
* rules apply:
@ -775,15 +770,14 @@ again:
if (status)
goto again;
if (++cpuc->interrupts != PERFMON_MAX_INTERRUPTS)
perf_enable();
perf_enable();
return 1;
}
static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi)
{
int cpu, idx, throttle = 0, handled = 0;
int cpu, idx, handled = 0;
struct cpu_hw_counters *cpuc;
struct perf_counter *counter;
struct hw_perf_counter *hwc;
@ -792,16 +786,7 @@ static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi)
cpu = smp_processor_id();
cpuc = &per_cpu(cpu_hw_counters, cpu);
if (++cpuc->interrupts == PERFMON_MAX_INTERRUPTS) {
throttle = 1;
__perf_disable();
cpuc->enabled = 0;
barrier();
}
for (idx = 0; idx < x86_pmu.num_counters; idx++) {
int disable = 0;
if (!test_bit(idx, cpuc->active_mask))
continue;
@ -809,45 +794,23 @@ static int amd_pmu_handle_irq(struct pt_regs *regs, int nmi)
hwc = &counter->hw;
if (counter->hw_event.nmi != nmi)
goto next;
continue;
val = x86_perf_counter_update(counter, hwc, idx);
if (val & (1ULL << (x86_pmu.counter_bits - 1)))
goto next;
continue;
/* counter overflow */
x86_perf_counter_set_period(counter, hwc, idx);
handled = 1;
inc_irq_stat(apic_perf_irqs);
disable = perf_counter_overflow(counter, nmi, regs, 0);
next:
if (disable || throttle)
if (perf_counter_overflow(counter, nmi, regs, 0))
amd_pmu_disable_counter(hwc, idx);
}
return handled;
}
void perf_counter_unthrottle(void)
{
struct cpu_hw_counters *cpuc;
if (!x86_pmu_initialized())
return;
cpuc = &__get_cpu_var(cpu_hw_counters);
if (cpuc->interrupts >= PERFMON_MAX_INTERRUPTS) {
/*
* Clear them before re-enabling irqs/NMIs again:
*/
cpuc->interrupts = 0;
perf_enable();
} else {
cpuc->interrupts = 0;
}
}
void smp_perf_counter_interrupt(struct pt_regs *regs)
{
irq_enter();

2
include/linux/perf_counter.h
View File

@ -570,7 +570,6 @@ extern int perf_counter_init_task(struct task_struct *child);
extern void perf_counter_exit_task(struct task_struct *child);
extern void perf_counter_do_pending(void);
extern void perf_counter_print_debug(void);
extern void perf_counter_unthrottle(void);
extern void __perf_disable(void);
extern bool __perf_enable(void);
extern void perf_disable(void);
@ -635,7 +634,6 @@ static inline int perf_counter_init_task(struct task_struct *child) { }
static inline void perf_counter_exit_task(struct task_struct *child) { }
static inline void perf_counter_do_pending(void) { }
static inline void perf_counter_print_debug(void) { }
static inline void perf_counter_unthrottle(void) { }
static inline void perf_disable(void) { }
static inline void perf_enable(void) { }
static inline int perf_counter_task_disable(void) { return -EINVAL; }