From 6a930700c8b655a9e25e42fc4adc0b225ebbcefc Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 11 Dec 2008 15:17:03 +0100 Subject: [PATCH] perf counters: clean up state transitions Impact: cleanup Introduce a proper enum for the 3 states of a counter: PERF_COUNTER_STATE_OFF = -1 PERF_COUNTER_STATE_INACTIVE = 0 PERF_COUNTER_STATE_ACTIVE = 1 and rename counter->active to counter->state and propagate the changes everywhere. Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_counter.c | 2 +- include/linux/perf_counter.h | 11 ++++++++++- kernel/perf_counter.c | 29 ++++++++++++++--------------- 3 files changed, 25 insertions(+), 17 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 3e1dbebe22b..4854cca7fff 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -332,7 +332,7 @@ perf_handle_group(struct perf_counter *sibling, u64 *status, u64 *overflown) * Then store sibling timestamps (if any): */ list_for_each_entry(counter, &group_leader->sibling_list, list_entry) { - if (!counter->active) { + if (counter->state != PERF_COUNTER_STATE_ACTIVE) { /* * When counter was not in the overflow mask, we have to * read it from hardware. We read it as well, when it diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 97d86c293ee..8cb095fa442 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -127,6 +127,15 @@ struct hw_perf_counter_ops { void (*hw_perf_counter_read) (struct perf_counter *counter); }; +/** + * enum perf_counter_active_state - the states of a counter + */ +enum perf_counter_active_state { + PERF_COUNTER_STATE_OFF = -1, + PERF_COUNTER_STATE_INACTIVE = 0, + PERF_COUNTER_STATE_ACTIVE = 1, +}; + /** * struct perf_counter - performance counter kernel representation: */ @@ -136,7 +145,7 @@ struct perf_counter { struct perf_counter *group_leader; const struct hw_perf_counter_ops *hw_ops; - int active; + enum perf_counter_active_state state; #if BITS_PER_LONG == 64 atomic64_t count; #else diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 4e679b91d8b..559130b8774 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -167,9 +167,9 @@ static void __perf_counter_remove_from_context(void *info) spin_lock(&ctx->lock); - if (counter->active) { + if (counter->state == PERF_COUNTER_STATE_ACTIVE) { counter->hw_ops->hw_perf_counter_disable(counter); - counter->active = 0; + counter->state = PERF_COUNTER_STATE_INACTIVE; ctx->nr_active--; cpuctx->active_oncpu--; counter->task = NULL; @@ -281,7 +281,7 @@ static void __perf_install_in_context(void *info) if (cpuctx->active_oncpu < perf_max_counters) { counter->hw_ops->hw_perf_counter_enable(counter); - counter->active = 1; + counter->state = PERF_COUNTER_STATE_ACTIVE; counter->oncpu = cpu; ctx->nr_active++; cpuctx->active_oncpu++; @@ -328,7 +328,6 @@ retry: spin_lock_irq(&ctx->lock); /* - * If the context is active and the counter has not been added * we need to retry the smp call. */ if (ctx->nr_active && list_empty(&counter->list_entry)) { @@ -353,12 +352,12 @@ counter_sched_out(struct perf_counter *counter, struct perf_cpu_context *cpuctx, struct perf_counter_context *ctx) { - if (!counter->active) + if (counter->state != PERF_COUNTER_STATE_ACTIVE) return; counter->hw_ops->hw_perf_counter_disable(counter); - counter->active = 0; - counter->oncpu = -1; + counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->oncpu = -1; cpuctx->active_oncpu--; ctx->nr_active--; @@ -415,11 +414,11 @@ counter_sched_in(struct perf_counter *counter, struct perf_counter_context *ctx, int cpu) { - if (counter->active == -1) + if (counter->state == PERF_COUNTER_STATE_OFF) return; counter->hw_ops->hw_perf_counter_enable(counter); - counter->active = 1; + counter->state = PERF_COUNTER_STATE_ACTIVE; counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ cpuctx->active_oncpu++; @@ -506,8 +505,8 @@ int perf_counter_task_disable(void) 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; + WARN_ON_ONCE(counter->state == PERF_COUNTER_STATE_ACTIVE); + counter->state = PERF_COUNTER_STATE_OFF; } hw_perf_restore(perf_flags); @@ -540,9 +539,9 @@ int perf_counter_task_enable(void) perf_flags = hw_perf_save_disable(); list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter->active != -1) + if (counter->state != PERF_COUNTER_STATE_OFF) continue; - counter->active = 0; + counter->state = PERF_COUNTER_STATE_INACTIVE; } hw_perf_restore(perf_flags); @@ -620,7 +619,7 @@ static u64 perf_counter_read(struct perf_counter *counter) * If counter is enabled and currently active on a CPU, update the * value in the counter structure: */ - if (counter->active) { + if (counter->state == PERF_COUNTER_STATE_ACTIVE) { smp_call_function_single(counter->oncpu, __hw_perf_counter_read, counter, 1); } @@ -673,7 +672,7 @@ static struct perf_data *perf_switch_irq_data(struct perf_counter *counter) retry: spin_lock_irq(&ctx->lock); - if (!counter->active) { + if (counter->state != PERF_COUNTER_STATE_ACTIVE) { counter->irqdata = counter->usrdata; counter->usrdata = oldirqdata; spin_unlock_irq(&ctx->lock); -- 2.39.5