diff options
| -rw-r--r-- | arch/powerpc/kernel/perf_counter.c | 10 | ||||
| -rw-r--r-- | include/linux/perf_counter.h | 15 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 226 |
3 files changed, 169 insertions, 82 deletions
diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c index 85ad259..5b02113 100644 --- a/arch/powerpc/kernel/perf_counter.c +++ b/arch/powerpc/kernel/perf_counter.c @@ -36,14 +36,6 @@ void perf_counter_print_debug(void) } /* - * Return 1 for a software counter, 0 for a hardware counter - */ -static inline int is_software_counter(struct perf_counter *counter) -{ - return !counter->hw_event.raw && counter->hw_event.type < 0; -} - -/* * Read one performance monitor counter (PMC). */ static unsigned long read_pmc(int idx) @@ -443,6 +435,7 @@ int hw_perf_group_sched_in(struct perf_counter *group_leader, */ for (i = n0; i < n0 + n; ++i) cpuhw->counter[i]->hw.config = cpuhw->events[i]; + cpuctx->active_oncpu += n; n = 1; counter_sched_in(group_leader, cpu); list_for_each_entry(sub, &group_leader->sibling_list, list_entry) { @@ -451,7 +444,6 @@ int hw_perf_group_sched_in(struct perf_counter *group_leader, ++n; } } - cpuctx->active_oncpu += n; ctx->nr_active += n; return 1; diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index b21d1ea..7ab8e5f 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -86,7 +86,10 @@ struct perf_counter_hw_event { nmi : 1, /* NMI sampling */ raw : 1, /* raw event type */ inherit : 1, /* children inherit it */ - __reserved_1 : 28; + pinned : 1, /* must always be on PMU */ + exclusive : 1, /* only counter on PMU */ + + __reserved_1 : 26; u64 __reserved_2; }; @@ -141,6 +144,7 @@ struct hw_perf_counter_ops { * enum perf_counter_active_state - the states of a counter */ enum perf_counter_active_state { + PERF_COUNTER_STATE_ERROR = -2, PERF_COUNTER_STATE_OFF = -1, PERF_COUNTER_STATE_INACTIVE = 0, PERF_COUNTER_STATE_ACTIVE = 1, @@ -214,6 +218,7 @@ struct perf_cpu_context { struct perf_counter_context *task_ctx; int active_oncpu; int max_pertask; + int exclusive; }; /* @@ -240,6 +245,14 @@ extern int hw_perf_group_sched_in(struct perf_counter *group_leader, struct perf_cpu_context *cpuctx, struct perf_counter_context *ctx, int cpu); +/* + * Return 1 for a software counter, 0 for a hardware counter + */ +static inline int is_software_counter(struct perf_counter *counter) +{ + return !counter->hw_event.raw && counter->hw_event.type < 0; +} + #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 52f2f52..faf671b 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -93,6 +93,25 @@ list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) } } +static void +counter_sched_out(struct perf_counter *counter, + struct perf_cpu_context *cpuctx, + struct perf_counter_context *ctx) +{ + if (counter->state != PERF_COUNTER_STATE_ACTIVE) + return; + + counter->state = PERF_COUNTER_STATE_INACTIVE; + counter->hw_ops->disable(counter); + counter->oncpu = -1; + + if (!is_software_counter(counter)) + cpuctx->active_oncpu--; + ctx->nr_active--; + if (counter->hw_event.exclusive || !cpuctx->active_oncpu) + cpuctx->exclusive = 0; +} + /* * Cross CPU call to remove a performance counter * @@ -118,14 +137,9 @@ static void __perf_counter_remove_from_context(void *info) curr_rq_lock_irq_save(&flags); spin_lock(&ctx->lock); - if (counter->state == PERF_COUNTER_STATE_ACTIVE) { - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->hw_ops->disable(counter); - ctx->nr_active--; - cpuctx->active_oncpu--; - counter->task = NULL; - counter->oncpu = -1; - } + counter_sched_out(counter, cpuctx, ctx); + + counter->task = NULL; ctx->nr_counters--; /* @@ -207,7 +221,7 @@ counter_sched_in(struct perf_counter *counter, struct perf_counter_context *ctx, int cpu) { - if (counter->state == PERF_COUNTER_STATE_OFF) + if (counter->state <= PERF_COUNTER_STATE_OFF) return 0; counter->state = PERF_COUNTER_STATE_ACTIVE; @@ -223,13 +237,64 @@ counter_sched_in(struct perf_counter *counter, return -EAGAIN; } - cpuctx->active_oncpu++; + if (!is_software_counter(counter)) + cpuctx->active_oncpu++; ctx->nr_active++; + if (counter->hw_event.exclusive) + cpuctx->exclusive = 1; + return 0; } /* + * Return 1 for a group consisting entirely of software counters, + * 0 if the group contains any hardware counters. + */ +static int is_software_only_group(struct perf_counter *leader) +{ + struct perf_counter *counter; + + if (!is_software_counter(leader)) + return 0; + list_for_each_entry(counter, &leader->sibling_list, list_entry) + if (!is_software_counter(counter)) + return 0; + return 1; +} + +/* + * Work out whether we can put this counter group on the CPU now. + */ +static int group_can_go_on(struct perf_counter *counter, + struct perf_cpu_context *cpuctx, + int can_add_hw) +{ + /* + * Groups consisting entirely of software counters can always go on. + */ + if (is_software_only_group(counter)) + return 1; + /* + * If an exclusive group is already on, no other hardware + * counters can go on. + */ + if (cpuctx->exclusive) + return 0; + /* + * If this group is exclusive and there are already + * counters on the CPU, it can't go on. + */ + if (counter->hw_event.exclusive && cpuctx->active_oncpu) + return 0; + /* + * Otherwise, try to add it if all previous groups were able + * to go on. + */ + return can_add_hw; +} + +/* * Cross CPU call to install and enable a performance counter */ static void __perf_install_in_context(void *info) @@ -240,6 +305,7 @@ static void __perf_install_in_context(void *info) int cpu = smp_processor_id(); unsigned long flags; u64 perf_flags; + int err; /* * If this is a task context, we need to check whether it is @@ -261,9 +327,21 @@ static void __perf_install_in_context(void *info) list_add_counter(counter, ctx); ctx->nr_counters++; - counter_sched_in(counter, cpuctx, ctx, cpu); + /* + * An exclusive counter can't go on if there are already active + * hardware counters, and no hardware counter can go on if there + * is already an exclusive counter on. + */ + if (counter->state == PERF_COUNTER_STATE_INACTIVE && + !group_can_go_on(counter, cpuctx, 1)) + err = -EEXIST; + else + err = counter_sched_in(counter, cpuctx, ctx, cpu); + + if (err && counter->hw_event.pinned) + counter->state = PERF_COUNTER_STATE_ERROR; - if (!ctx->task && cpuctx->max_pertask) + if (!err && !ctx->task && cpuctx->max_pertask) cpuctx->max_pertask--; hw_perf_restore(perf_flags); @@ -327,22 +405,6 @@ retry: } static void -counter_sched_out(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx) -{ - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - return; - - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->hw_ops->disable(counter); - counter->oncpu = -1; - - cpuctx->active_oncpu--; - ctx->nr_active--; -} - -static void group_sched_out(struct perf_counter *group_counter, struct perf_cpu_context *cpuctx, struct perf_counter_context *ctx) @@ -359,6 +421,9 @@ group_sched_out(struct perf_counter *group_counter, */ list_for_each_entry(counter, &group_counter->sibling_list, list_entry) counter_sched_out(counter, cpuctx, ctx); + + if (group_counter->hw_event.exclusive) + cpuctx->exclusive = 0; } void __perf_counter_sched_out(struct perf_counter_context *ctx, @@ -455,30 +520,6 @@ group_error: return -EAGAIN; } -/* - * Return 1 for a software counter, 0 for a hardware counter - */ -static inline int is_software_counter(struct perf_counter *counter) -{ - return !counter->hw_event.raw && counter->hw_event.type < 0; -} - -/* - * Return 1 for a group consisting entirely of software counters, - * 0 if the group contains any hardware counters. - */ -static int is_software_only_group(struct perf_counter *leader) -{ - struct perf_counter *counter; - - if (!is_software_counter(leader)) - return 0; - list_for_each_entry(counter, &leader->sibling_list, list_entry) - if (!is_software_counter(counter)) - return 0; - return 1; -} - static void __perf_counter_sched_in(struct perf_counter_context *ctx, struct perf_cpu_context *cpuctx, int cpu) @@ -492,22 +533,49 @@ __perf_counter_sched_in(struct perf_counter_context *ctx, spin_lock(&ctx->lock); flags = hw_perf_save_disable(); + + /* + * First go through the list and put on any pinned groups + * in order to give them the best chance of going on. + */ + list_for_each_entry(counter, &ctx->counter_list, list_entry) { + if (counter->state <= PERF_COUNTER_STATE_OFF || + !counter->hw_event.pinned) + continue; + if (counter->cpu != -1 && counter->cpu != cpu) + continue; + + if (group_can_go_on(counter, cpuctx, 1)) + group_sched_in(counter, cpuctx, ctx, cpu); + + /* + * If this pinned group hasn't been scheduled, + * put it in error state. + */ + if (counter->state == PERF_COUNTER_STATE_INACTIVE) + counter->state = PERF_COUNTER_STATE_ERROR; + } + list_for_each_entry(counter, &ctx->counter_list, list_entry) { /* + * Ignore counters in OFF or ERROR state, and + * ignore pinned counters since we did them already. + */ + if (counter->state <= PERF_COUNTER_STATE_OFF || + counter->hw_event.pinned) + continue; + + /* * Listen to the 'cpu' scheduling filter constraint * of counters: */ if (counter->cpu != -1 && counter->cpu != cpu) continue; - /* - * If we scheduled in a group atomically and exclusively, - * or if this group can't go on, don't add any more - * hardware counters. - */ - if (can_add_hw || is_software_only_group(counter)) + if (group_can_go_on(counter, cpuctx, can_add_hw)) { if (group_sched_in(counter, cpuctx, ctx, cpu)) can_add_hw = 0; + } } hw_perf_restore(flags); spin_unlock(&ctx->lock); @@ -567,8 +635,10 @@ int perf_counter_task_disable(void) */ perf_flags = hw_perf_save_disable(); - list_for_each_entry(counter, &ctx->counter_list, list_entry) - counter->state = PERF_COUNTER_STATE_OFF; + list_for_each_entry(counter, &ctx->counter_list, list_entry) { + if (counter->state != PERF_COUNTER_STATE_ERROR) + counter->state = PERF_COUNTER_STATE_OFF; + } hw_perf_restore(perf_flags); @@ -607,7 +677,7 @@ int perf_counter_task_enable(void) perf_flags = hw_perf_save_disable(); list_for_each_entry(counter, &ctx->counter_list, list_entry) { - if (counter->state != PERF_COUNTER_STATE_OFF) + if (counter->state > PERF_COUNTER_STATE_OFF) continue; counter->state = PERF_COUNTER_STATE_INACTIVE; counter->hw_event.disabled = 0; @@ -849,6 +919,14 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) if (count != sizeof(cntval)) return -EINVAL; + /* + * Return end-of-file for a read on a counter that is in + * error state (i.e. because it was pinned but it couldn't be + * scheduled on to the CPU at some point). + */ + if (counter->state == PERF_COUNTER_STATE_ERROR) + return 0; + mutex_lock(&counter->mutex); cntval = perf_counter_read(counter); mutex_unlock(&counter->mutex); @@ -884,7 +962,7 @@ perf_read_irq_data(struct perf_counter *counter, { struct perf_data *irqdata, *usrdata; DECLARE_WAITQUEUE(wait, current); - ssize_t res; + ssize_t res, res2; irqdata = counter->irqdata; usrdata = counter->usrdata; @@ -905,6 +983,9 @@ perf_read_irq_data(struct perf_counter *counter, if (signal_pending(current)) break; + if (counter->state == PERF_COUNTER_STATE_ERROR) + break; + spin_unlock_irq(&counter->waitq.lock); schedule(); spin_lock_irq(&counter->waitq.lock); @@ -913,7 +994,8 @@ perf_read_irq_data(struct perf_counter *counter, __set_current_state(TASK_RUNNING); spin_unlock_irq(&counter->waitq.lock); - if (usrdata->len + irqdata->len < count) + if (usrdata->len + irqdata->len < count && + counter->state != PERF_COUNTER_STATE_ERROR) return -ERESTARTSYS; read_pending: mutex_lock(&counter->mutex); @@ -925,11 +1007,12 @@ read_pending: /* Switch irq buffer: */ usrdata = perf_switch_irq_data(counter); - if (perf_copy_usrdata(usrdata, buf + res, count - res) < 0) { + res2 = perf_copy_usrdata(usrdata, buf + res, count - res); + if (res2 < 0) { if (!res) res = -EFAULT; } else { - res = count; + res += res2; } out: mutex_unlock(&counter->mutex); @@ -1348,6 +1431,11 @@ sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user, */ if (group_leader->ctx != ctx) goto err_put_context; + /* + * Only a group leader can be exclusive or pinned + */ + if (hw_event.exclusive || hw_event.pinned) + goto err_put_context; } ret = -EINVAL; @@ -1473,13 +1561,7 @@ __perf_counter_exit_task(struct task_struct *child, cpuctx = &__get_cpu_var(perf_cpu_context); - if (child_counter->state == PERF_COUNTER_STATE_ACTIVE) { - child_counter->state = PERF_COUNTER_STATE_INACTIVE; - child_counter->hw_ops->disable(child_counter); - cpuctx->active_oncpu--; - child_ctx->nr_active--; - child_counter->oncpu = -1; - } + counter_sched_out(child_counter, cpuctx, child_ctx); list_del_init(&child_counter->list_entry); 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