diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 6 | ||||
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 62 |
3 files changed, 51 insertions, 19 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index b6755712142..74090a393a7 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -244,7 +244,7 @@ static int fixed_mode_idx(struct hw_perf_counter *hwc) /* * Find a PMC slot for the freshly enabled / scheduled in counter: */ -static void pmc_generic_enable(struct perf_counter *counter) +static int pmc_generic_enable(struct perf_counter *counter) { struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters); struct hw_perf_counter *hwc = &counter->hw; @@ -253,6 +253,8 @@ static void pmc_generic_enable(struct perf_counter *counter) /* Try to get the previous counter again */ if (test_and_set_bit(idx, cpuc->used)) { idx = find_first_zero_bit(cpuc->used, nr_counters_generic); + if (idx == nr_counters_generic) + return -EAGAIN; set_bit(idx, cpuc->used); hwc->idx = idx; } @@ -265,6 +267,8 @@ static void pmc_generic_enable(struct perf_counter *counter) __hw_perf_counter_set_period(counter, hwc, idx); __pmc_generic_enable(counter, hwc, idx); + + return 0; } void perf_counter_print_debug(void) diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 48f76d2e54c..53af11d3767 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -128,7 +128,7 @@ struct perf_counter; * struct hw_perf_counter_ops - performance counter hw ops */ struct hw_perf_counter_ops { - void (*enable) (struct perf_counter *counter); + int (*enable) (struct perf_counter *counter); void (*disable) (struct perf_counter *counter); void (*read) (struct perf_counter *counter); }; diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index f1110ac1267..2e73929a695 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -355,21 +355,25 @@ void perf_counter_task_sched_out(struct task_struct *task, int cpu) cpuctx->task_ctx = NULL; } -static void +static int counter_sched_in(struct perf_counter *counter, struct perf_cpu_context *cpuctx, struct perf_counter_context *ctx, int cpu) { if (counter->state == PERF_COUNTER_STATE_OFF) - return; + return 0; + + if (counter->hw_ops->enable(counter)) + return -EAGAIN; - counter->hw_ops->enable(counter); counter->state = PERF_COUNTER_STATE_ACTIVE; counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ cpuctx->active_oncpu++; ctx->nr_active++; + + return 0; } static int @@ -378,20 +382,38 @@ group_sched_in(struct perf_counter *group_counter, struct perf_counter_context *ctx, int cpu) { - struct perf_counter *counter; - int was_group = 0; + struct perf_counter *counter, *partial_group; + int ret = 0; - counter_sched_in(group_counter, cpuctx, ctx, cpu); + if (counter_sched_in(group_counter, cpuctx, ctx, cpu)) + return -EAGAIN; /* * Schedule in siblings as one group (if any): */ list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { - counter_sched_in(counter, cpuctx, ctx, cpu); - was_group = 1; + if (counter_sched_in(counter, cpuctx, ctx, cpu)) { + partial_group = counter; + goto group_error; + } + ret = -EAGAIN; } - return was_group; + return ret; + +group_error: + /* + * Groups can be scheduled in as one unit only, so undo any + * partial group before returning: + */ + list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { + if (counter == partial_group) + break; + counter_sched_out(counter, cpuctx, ctx); + } + counter_sched_out(group_counter, cpuctx, ctx); + + return -EAGAIN; } /* @@ -416,9 +438,6 @@ void perf_counter_task_sched_in(struct task_struct *task, int cpu) spin_lock(&ctx->lock); list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (ctx->nr_active == cpuctx->max_pertask) - break; - /* * Listen to the 'cpu' scheduling filter constraint * of counters: @@ -856,8 +875,9 @@ static const struct file_operations perf_fops = { .poll = perf_poll, }; -static void cpu_clock_perf_counter_enable(struct perf_counter *counter) +static int cpu_clock_perf_counter_enable(struct perf_counter *counter) { + return 0; } static void cpu_clock_perf_counter_disable(struct perf_counter *counter) @@ -913,11 +933,13 @@ static void task_clock_perf_counter_read(struct perf_counter *counter) task_clock_perf_counter_update(counter, now); } -static void task_clock_perf_counter_enable(struct perf_counter *counter) +static int task_clock_perf_counter_enable(struct perf_counter *counter) { u64 now = task_clock_perf_counter_val(counter, 0); atomic64_set(&counter->hw.prev_count, now); + + return 0; } static void task_clock_perf_counter_disable(struct perf_counter *counter) @@ -960,12 +982,14 @@ static void page_faults_perf_counter_read(struct perf_counter *counter) page_faults_perf_counter_update(counter); } -static void page_faults_perf_counter_enable(struct perf_counter *counter) +static int page_faults_perf_counter_enable(struct perf_counter *counter) { /* * page-faults is a per-task value already, * so we dont have to clear it on switch-in. */ + + return 0; } static void page_faults_perf_counter_disable(struct perf_counter *counter) @@ -1006,12 +1030,14 @@ static void context_switches_perf_counter_read(struct perf_counter *counter) context_switches_perf_counter_update(counter); } -static void context_switches_perf_counter_enable(struct perf_counter *counter) +static int context_switches_perf_counter_enable(struct perf_counter *counter) { /* * ->nvcsw + curr->nivcsw is a per-task value already, * so we dont have to clear it on switch-in. */ + + return 0; } static void context_switches_perf_counter_disable(struct perf_counter *counter) @@ -1050,12 +1076,14 @@ static void cpu_migrations_perf_counter_read(struct perf_counter *counter) cpu_migrations_perf_counter_update(counter); } -static void cpu_migrations_perf_counter_enable(struct perf_counter *counter) +static int cpu_migrations_perf_counter_enable(struct perf_counter *counter) { /* * se.nr_migrations is a per-task value already, * so we dont have to clear it on switch-in. */ + + return 0; } static void cpu_migrations_perf_counter_disable(struct perf_counter *counter) |