diff options
| -rw-r--r-- | arch/powerpc/kernel/perf_counter.c | 2 | ||||
| -rw-r--r-- | include/linux/perf_counter.h | 53 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 157 |
3 files changed, 191 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c index d48596ab655..df007fe0cc0 100644 --- a/arch/powerpc/kernel/perf_counter.c +++ b/arch/powerpc/kernel/perf_counter.c @@ -455,6 +455,8 @@ static void counter_sched_in(struct perf_counter *counter, int cpu) { counter->state = PERF_COUNTER_STATE_ACTIVE; counter->oncpu = cpu; + counter->tstamp_running += counter->ctx->time_now - + counter->tstamp_stopped; if (is_software_counter(counter)) counter->hw_ops->enable(counter); } diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 7fdbdf8be77..6bf67ce1762 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -103,6 +103,16 @@ enum perf_counter_record_type { #define PERF_COUNTER_EVENT_MASK __PERF_COUNTER_MASK(EVENT) /* + * Bits that can be set in hw_event.read_format to request that + * reads on the counter should return the indicated quantities, + * in increasing order of bit value, after the counter value. + */ +enum perf_counter_read_format { + PERF_FORMAT_TOTAL_TIME_ENABLED = 1, + PERF_FORMAT_TOTAL_TIME_RUNNING = 2, +}; + +/* * Hardware event to monitor via a performance monitoring counter: */ struct perf_counter_hw_event { @@ -281,6 +291,32 @@ struct perf_counter { enum perf_counter_active_state prev_state; atomic64_t count; + /* + * These are the total time in nanoseconds that the counter + * has been enabled (i.e. eligible to run, and the task has + * been scheduled in, if this is a per-task counter) + * and running (scheduled onto the CPU), respectively. + * + * They are computed from tstamp_enabled, tstamp_running and + * tstamp_stopped when the counter is in INACTIVE or ACTIVE state. + */ + u64 total_time_enabled; + u64 total_time_running; + + /* + * These are timestamps used for computing total_time_enabled + * and total_time_running when the counter is in INACTIVE or + * ACTIVE state, measured in nanoseconds from an arbitrary point + * in time. + * tstamp_enabled: the notional time when the counter was enabled + * tstamp_running: the notional time when the counter was scheduled on + * tstamp_stopped: in INACTIVE state, the notional time when the + * counter was scheduled off. + */ + u64 tstamp_enabled; + u64 tstamp_running; + u64 tstamp_stopped; + struct perf_counter_hw_event hw_event; struct hw_perf_counter hw; @@ -292,6 +328,13 @@ struct perf_counter { struct list_head child_list; /* + * These accumulate total time (in nanoseconds) that children + * counters have been enabled and running, respectively. + */ + atomic64_t child_total_time_enabled; + atomic64_t child_total_time_running; + + /* * Protect attach/detach and child_list: */ struct mutex mutex; @@ -339,6 +382,16 @@ struct perf_counter_context { int nr_active; int is_active; struct task_struct *task; + + /* + * time_now is the current time in nanoseconds since an arbitrary + * point in the past. For per-task counters, this is based on the + * task clock, and for per-cpu counters it is based on the cpu clock. + * time_lost is an offset from the task/cpu clock, used to make it + * appear that time only passes while the context is scheduled in. + */ + u64 time_now; + u64 time_lost; #endif }; diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 95e02575546..3b862a7988c 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -116,6 +116,7 @@ counter_sched_out(struct perf_counter *counter, return; counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->tstamp_stopped = ctx->time_now; counter->hw_ops->disable(counter); counter->oncpu = -1; @@ -252,6 +253,60 @@ retry: } /* + * Get the current time for this context. + * If this is a task context, we use the task's task clock, + * or for a per-cpu context, we use the cpu clock. + */ +static u64 get_context_time(struct perf_counter_context *ctx, int update) +{ + struct task_struct *curr = ctx->task; + + if (!curr) + return cpu_clock(smp_processor_id()); + + return __task_delta_exec(curr, update) + curr->se.sum_exec_runtime; +} + +/* + * Update the record of the current time in a context. + */ +static void update_context_time(struct perf_counter_context *ctx, int update) +{ + ctx->time_now = get_context_time(ctx, update) - ctx->time_lost; +} + +/* + * Update the total_time_enabled and total_time_running fields for a counter. + */ +static void update_counter_times(struct perf_counter *counter) +{ + struct perf_counter_context *ctx = counter->ctx; + u64 run_end; + + if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { + counter->total_time_enabled = ctx->time_now - + counter->tstamp_enabled; + if (counter->state == PERF_COUNTER_STATE_INACTIVE) + run_end = counter->tstamp_stopped; + else + run_end = ctx->time_now; + counter->total_time_running = run_end - counter->tstamp_running; + } +} + +/* + * Update total_time_enabled and total_time_running for all counters in a group. + */ +static void update_group_times(struct perf_counter *leader) +{ + struct perf_counter *counter; + + update_counter_times(leader); + list_for_each_entry(counter, &leader->sibling_list, list_entry) + update_counter_times(counter); +} + +/* * Cross CPU call to disable a performance counter */ static void __perf_counter_disable(void *info) @@ -276,6 +331,8 @@ static void __perf_counter_disable(void *info) * If it is in error state, leave it in error state. */ if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { + update_context_time(ctx, 1); + update_counter_times(counter); if (counter == counter->group_leader) group_sched_out(counter, cpuctx, ctx); else @@ -320,8 +377,10 @@ static void perf_counter_disable(struct perf_counter *counter) * Since we have the lock this context can't be scheduled * in, so we can change the state safely. */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) + if (counter->state == PERF_COUNTER_STATE_INACTIVE) { + update_counter_times(counter); counter->state = PERF_COUNTER_STATE_OFF; + } spin_unlock_irq(&ctx->lock); } @@ -366,6 +425,8 @@ counter_sched_in(struct perf_counter *counter, return -EAGAIN; } + counter->tstamp_running += ctx->time_now - counter->tstamp_stopped; + if (!is_software_counter(counter)) cpuctx->active_oncpu++; ctx->nr_active++; @@ -425,6 +486,17 @@ static int group_can_go_on(struct perf_counter *counter, return can_add_hw; } +static void add_counter_to_ctx(struct perf_counter *counter, + struct perf_counter_context *ctx) +{ + list_add_counter(counter, ctx); + ctx->nr_counters++; + counter->prev_state = PERF_COUNTER_STATE_OFF; + counter->tstamp_enabled = ctx->time_now; + counter->tstamp_running = ctx->time_now; + counter->tstamp_stopped = ctx->time_now; +} + /* * Cross CPU call to install and enable a performance counter */ @@ -449,6 +521,7 @@ static void __perf_install_in_context(void *info) curr_rq_lock_irq_save(&flags); spin_lock(&ctx->lock); + update_context_time(ctx, 1); /* * Protect the list operation against NMI by disabling the @@ -456,9 +529,7 @@ static void __perf_install_in_context(void *info) */ perf_flags = hw_perf_save_disable(); - list_add_counter(counter, ctx); - ctx->nr_counters++; - counter->prev_state = PERF_COUNTER_STATE_OFF; + add_counter_to_ctx(counter, ctx); /* * Don't put the counter on if it is disabled or if @@ -486,8 +557,10 @@ static void __perf_install_in_context(void *info) */ if (leader != counter) group_sched_out(leader, cpuctx, ctx); - if (leader->hw_event.pinned) + if (leader->hw_event.pinned) { + update_group_times(leader); leader->state = PERF_COUNTER_STATE_ERROR; + } } if (!err && !ctx->task && cpuctx->max_pertask) @@ -548,10 +621,8 @@ retry: * can add the counter safely, if it the call above did not * succeed. */ - if (list_empty(&counter->list_entry)) { - list_add_counter(counter, ctx); - ctx->nr_counters++; - } + if (list_empty(&counter->list_entry)) + add_counter_to_ctx(counter, ctx); spin_unlock_irq(&ctx->lock); } @@ -576,11 +647,13 @@ static void __perf_counter_enable(void *info) curr_rq_lock_irq_save(&flags); spin_lock(&ctx->lock); + update_context_time(ctx, 1); counter->prev_state = counter->state; if (counter->state >= PERF_COUNTER_STATE_INACTIVE) goto unlock; counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->tstamp_enabled = ctx->time_now - counter->total_time_enabled; /* * If the counter is in a group and isn't the group leader, @@ -602,8 +675,10 @@ static void __perf_counter_enable(void *info) */ if (leader != counter) group_sched_out(leader, cpuctx, ctx); - if (leader->hw_event.pinned) + if (leader->hw_event.pinned) { + update_group_times(leader); leader->state = PERF_COUNTER_STATE_ERROR; + } } unlock: @@ -659,8 +734,11 @@ static void perf_counter_enable(struct perf_counter *counter) * Since we have the lock this context can't be scheduled * in, so we can change the state safely. */ - if (counter->state == PERF_COUNTER_STATE_OFF) + if (counter->state == PERF_COUNTER_STATE_OFF) { counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->tstamp_enabled = ctx->time_now - + counter->total_time_enabled; + } out: spin_unlock_irq(&ctx->lock); } @@ -693,6 +771,7 @@ void __perf_counter_sched_out(struct perf_counter_context *ctx, ctx->is_active = 0; if (likely(!ctx->nr_counters)) goto out; + update_context_time(ctx, 0); flags = hw_perf_save_disable(); if (ctx->nr_active) { @@ -797,6 +876,13 @@ __perf_counter_sched_in(struct perf_counter_context *ctx, if (likely(!ctx->nr_counters)) goto out; + /* + * Add any time since the last sched_out to the lost time + * so it doesn't get included in the total_time_enabled and + * total_time_running measures for counters in the context. + */ + ctx->time_lost = get_context_time(ctx, 0) - ctx->time_now; + flags = hw_perf_save_disable(); /* @@ -817,8 +903,10 @@ __perf_counter_sched_in(struct perf_counter_context *ctx, * If this pinned group hasn't been scheduled, * put it in error state. */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) + if (counter->state == PERF_COUNTER_STATE_INACTIVE) { + update_group_times(counter); counter->state = PERF_COUNTER_STATE_ERROR; + } } list_for_each_entry(counter, &ctx->counter_list, list_entry) { @@ -902,8 +990,10 @@ int perf_counter_task_disable(void) perf_flags = hw_perf_save_disable(); list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter->state != PERF_COUNTER_STATE_ERROR) + if (counter->state != PERF_COUNTER_STATE_ERROR) { + update_group_times(counter); counter->state = PERF_COUNTER_STATE_OFF; + } } hw_perf_restore(perf_flags); @@ -946,6 +1036,8 @@ int perf_counter_task_enable(void) if (counter->state > PERF_COUNTER_STATE_OFF) continue; counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->tstamp_enabled = ctx->time_now - + counter->total_time_enabled; counter->hw_event.disabled = 0; } hw_perf_restore(perf_flags); @@ -1009,10 +1101,14 @@ void perf_counter_task_tick(struct task_struct *curr, int cpu) static void __read(void *info) { struct perf_counter *counter = info; + struct perf_counter_context *ctx = counter->ctx; unsigned long flags; curr_rq_lock_irq_save(&flags); + if (ctx->is_active) + update_context_time(ctx, 1); counter->hw_ops->read(counter); + update_counter_times(counter); curr_rq_unlock_irq_restore(&flags); } @@ -1025,6 +1121,8 @@ static u64 perf_counter_read(struct perf_counter *counter) if (counter->state == PERF_COUNTER_STATE_ACTIVE) { smp_call_function_single(counter->oncpu, __read, counter, 1); + } else if (counter->state == PERF_COUNTER_STATE_INACTIVE) { + update_counter_times(counter); } return atomic64_read(&counter->count); @@ -1137,10 +1235,8 @@ static int perf_release(struct inode *inode, struct file *file) static ssize_t perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) { - u64 cntval; - - if (count < sizeof(cntval)) - return -EINVAL; + u64 values[3]; + int n; /* * Return end-of-file for a read on a counter that is in @@ -1151,10 +1247,24 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) return 0; mutex_lock(&counter->mutex); - cntval = perf_counter_read(counter); + values[0] = perf_counter_read(counter); + n = 1; + if (counter->hw_event.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + values[n++] = counter->total_time_enabled + + atomic64_read(&counter->child_total_time_enabled); + if (counter->hw_event.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + values[n++] = counter->total_time_running + + atomic64_read(&counter->child_total_time_running); mutex_unlock(&counter->mutex); - return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval); + if (count < n * sizeof(u64)) + return -EINVAL; + count = n * sizeof(u64); + + if (copy_to_user(buf, values, count)) + return -EFAULT; + + return count; } static ssize_t @@ -2290,8 +2400,7 @@ inherit_counter(struct perf_counter *parent_counter, * Link it up in the child's context: */ child_counter->task = child; - list_add_counter(child_counter, child_ctx); - child_ctx->nr_counters++; + add_counter_to_ctx(child_counter, child_ctx); child_counter->parent = parent_counter; /* @@ -2361,6 +2470,10 @@ static void sync_child_counter(struct perf_counter *child_counter, * Add back the child's count to the parent's count: */ atomic64_add(child_val, &parent_counter->count); + atomic64_add(child_counter->total_time_enabled, + &parent_counter->child_total_time_enabled); + atomic64_add(child_counter->total_time_running, + &parent_counter->child_total_time_running); /* * Remove this counter from the parent's list @@ -2395,6 +2508,7 @@ __perf_counter_exit_task(struct task_struct *child, if (child != current) { wait_task_inactive(child, 0); list_del_init(&child_counter->list_entry); + update_counter_times(child_counter); } else { struct perf_cpu_context *cpuctx; unsigned long flags; @@ -2412,6 +2526,7 @@ __perf_counter_exit_task(struct task_struct *child, cpuctx = &__get_cpu_var(perf_cpu_context); group_sched_out(child_counter, cpuctx, child_ctx); + update_counter_times(child_counter); list_del_init(&child_counter->list_entry); |