diff options
| -rw-r--r-- | include/linux/perf_counter.h | 4 | ||||
| -rw-r--r-- | include/linux/prctl.h | 3 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 86 | ||||
| -rw-r--r-- | kernel/sys.c | 7 |
4 files changed, 93 insertions, 7 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 30c0ec8c1ee..97d86c293ee 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -213,6 +213,8 @@ extern u64 hw_perf_save_disable(void); extern void hw_perf_restore(u64 ctrl); extern void atomic64_counter_set(struct perf_counter *counter, u64 val64); extern u64 atomic64_counter_read(struct perf_counter *counter); +extern int perf_counter_task_disable(void); +extern int perf_counter_task_enable(void); #else static inline void @@ -226,6 +228,8 @@ static inline void perf_counter_notify(struct pt_regs *regs) { } static inline void perf_counter_print_debug(void) { } static inline void hw_perf_restore(u64 ctrl) { } static inline u64 hw_perf_save_disable(void) { return 0; } +static inline int perf_counter_task_disable(void) { return -EINVAL; } +static inline int perf_counter_task_enable(void) { return -EINVAL; } #endif #endif /* _LINUX_PERF_COUNTER_H */ diff --git a/include/linux/prctl.h b/include/linux/prctl.h index 48d887e3c6e..b00df4c79c6 100644 --- a/include/linux/prctl.h +++ b/include/linux/prctl.h @@ -85,4 +85,7 @@ #define PR_SET_TIMERSLACK 29 #define PR_GET_TIMERSLACK 30 +#define PR_TASK_PERF_COUNTERS_DISABLE 31 +#define PR_TASK_PERF_COUNTERS_ENABLE 32 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index a0fe8474ee2..4e679b91d8b 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -415,6 +415,9 @@ counter_sched_in(struct perf_counter *counter, struct perf_counter_context *ctx, int cpu) { + if (counter->active == -1) + return; + counter->hw_ops->hw_perf_counter_enable(counter); counter->active = 1; counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ @@ -479,6 +482,79 @@ void perf_counter_task_sched_in(struct task_struct *task, int cpu) cpuctx->task_ctx = ctx; } +int perf_counter_task_disable(void) +{ + struct task_struct *curr = current; + struct perf_counter_context *ctx = &curr->perf_counter_ctx; + struct perf_counter *counter; + u64 perf_flags; + int cpu; + + if (likely(!ctx->nr_counters)) + return 0; + + local_irq_disable(); + cpu = smp_processor_id(); + + perf_counter_task_sched_out(curr, cpu); + + spin_lock(&ctx->lock); + + /* + * Disable all the counters: + */ + perf_flags = hw_perf_save_disable(); + + list_for_each_entry(counter, &ctx->counter_list, list_entry) { + WARN_ON_ONCE(counter->active == 1); + counter->active = -1; + } + hw_perf_restore(perf_flags); + + spin_unlock(&ctx->lock); + + local_irq_enable(); + + return 0; +} + +int perf_counter_task_enable(void) +{ + struct task_struct *curr = current; + struct perf_counter_context *ctx = &curr->perf_counter_ctx; + struct perf_counter *counter; + u64 perf_flags; + int cpu; + + if (likely(!ctx->nr_counters)) + return 0; + + local_irq_disable(); + cpu = smp_processor_id(); + + spin_lock(&ctx->lock); + + /* + * Disable all the counters: + */ + perf_flags = hw_perf_save_disable(); + + list_for_each_entry(counter, &ctx->counter_list, list_entry) { + if (counter->active != -1) + continue; + counter->active = 0; + } + hw_perf_restore(perf_flags); + + spin_unlock(&ctx->lock); + + perf_counter_task_sched_in(curr, cpu); + + local_irq_enable(); + + return 0; +} + void perf_counter_task_tick(struct task_struct *curr, int cpu) { struct perf_counter_context *ctx = &curr->perf_counter_ctx; @@ -951,13 +1027,9 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event, * @cpu: target cpu * @group_fd: group leader counter fd */ -asmlinkage int sys_perf_counter_open( - - struct perf_counter_hw_event *hw_event_uptr __user, - pid_t pid, - int cpu, - int group_fd) - +asmlinkage int +sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user, + pid_t pid, int cpu, int group_fd) { struct perf_counter *counter, *group_leader; struct perf_counter_hw_event hw_event; diff --git a/kernel/sys.c b/kernel/sys.c index 31deba8f7d1..0f66633be31 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -14,6 +14,7 @@ #include <linux/prctl.h> #include <linux/highuid.h> #include <linux/fs.h> +#include <linux/perf_counter.h> #include <linux/resource.h> #include <linux/kernel.h> #include <linux/kexec.h> @@ -1716,6 +1717,12 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, case PR_SET_TSC: error = SET_TSC_CTL(arg2); break; + case PR_TASK_PERF_COUNTERS_DISABLE: + error = perf_counter_task_disable(); + break; + case PR_TASK_PERF_COUNTERS_ENABLE: + error = perf_counter_task_enable(); + break; case PR_GET_TIMERSLACK: error = current->timer_slack_ns; break; |