diff options
Diffstat (limited to 'kernel/perf_event.c')
| -rw-r--r-- | kernel/perf_event.c | 1788 |
1 files changed, 1141 insertions, 647 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index d27746bd3a0..ff86c558af4 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -15,6 +15,8 @@ #include <linux/smp.h> #include <linux/file.h> #include <linux/poll.h> +#include <linux/slab.h> +#include <linux/hash.h> #include <linux/sysfs.h> #include <linux/dcache.h> #include <linux/percpu.h> @@ -56,21 +58,6 @@ static atomic_t nr_task_events __read_mostly; */ int sysctl_perf_event_paranoid __read_mostly = 1; -static inline bool perf_paranoid_tracepoint_raw(void) -{ - return sysctl_perf_event_paranoid > -1; -} - -static inline bool perf_paranoid_cpu(void) -{ - return sysctl_perf_event_paranoid > 0; -} - -static inline bool perf_paranoid_kernel(void) -{ - return sysctl_perf_event_paranoid > 1; -} - int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */ /* @@ -96,40 +83,19 @@ extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) void __weak hw_perf_disable(void) { barrier(); } void __weak hw_perf_enable(void) { barrier(); } -void __weak hw_perf_event_setup(int cpu) { barrier(); } -void __weak hw_perf_event_setup_online(int cpu) { barrier(); } - -int __weak -hw_perf_group_sched_in(struct perf_event *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx, int cpu) -{ - return 0; -} - void __weak perf_event_print_debug(void) { } static DEFINE_PER_CPU(int, perf_disable_count); -void __perf_disable(void) -{ - __get_cpu_var(perf_disable_count)++; -} - -bool __perf_enable(void) -{ - return !--__get_cpu_var(perf_disable_count); -} - void perf_disable(void) { - __perf_disable(); - hw_perf_disable(); + if (!__get_cpu_var(perf_disable_count)++) + hw_perf_disable(); } void perf_enable(void) { - if (__perf_enable()) + if (!--__get_cpu_var(perf_disable_count)) hw_perf_enable(); } @@ -248,7 +214,7 @@ static void perf_unpin_context(struct perf_event_context *ctx) static inline u64 perf_clock(void) { - return cpu_clock(smp_processor_id()); + return cpu_clock(raw_smp_processor_id()); } /* @@ -290,24 +256,49 @@ static void update_event_times(struct perf_event *event) } /* + * Update total_time_enabled and total_time_running for all events in a group. + */ +static void update_group_times(struct perf_event *leader) +{ + struct perf_event *event; + + update_event_times(leader); + list_for_each_entry(event, &leader->sibling_list, group_entry) + update_event_times(event); +} + +static struct list_head * +ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) +{ + if (event->attr.pinned) + return &ctx->pinned_groups; + else + return &ctx->flexible_groups; +} + +/* * Add a event from the lists for its context. * Must be called with ctx->mutex and ctx->lock held. */ static void list_add_event(struct perf_event *event, struct perf_event_context *ctx) { - struct perf_event *group_leader = event->group_leader; + WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); + event->attach_state |= PERF_ATTACH_CONTEXT; /* - * Depending on whether it is a standalone or sibling event, - * add it straight to the context's event list, or to the group - * leader's sibling list: + * If we're a stand alone event or group leader, we go to the context + * list, group events are kept attached to the group so that + * perf_group_detach can, at all times, locate all siblings. */ - if (group_leader == event) - list_add_tail(&event->group_entry, &ctx->group_list); - else { - list_add_tail(&event->group_entry, &group_leader->sibling_list); - group_leader->nr_siblings++; + if (event->group_leader == event) { + struct list_head *list; + + if (is_software_event(event)) + event->group_flags |= PERF_GROUP_SOFTWARE; + + list = ctx_group_list(event, ctx); + list_add_tail(&event->group_entry, list); } list_add_rcu(&event->event_entry, &ctx->event_list); @@ -316,6 +307,24 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) ctx->nr_stat++; } +static void perf_group_attach(struct perf_event *event) +{ + struct perf_event *group_leader = event->group_leader; + + WARN_ON_ONCE(event->attach_state & PERF_ATTACH_GROUP); + event->attach_state |= PERF_ATTACH_GROUP; + + if (group_leader == event) + return; + + if (group_leader->group_flags & PERF_GROUP_SOFTWARE && + !is_software_event(event)) + group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; + + list_add_tail(&event->group_entry, &group_leader->sibling_list); + group_leader->nr_siblings++; +} + /* * Remove a event from the lists for its context. * Must be called with ctx->mutex and ctx->lock held. @@ -323,21 +332,24 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) static void list_del_event(struct perf_event *event, struct perf_event_context *ctx) { - struct perf_event *sibling, *tmp; - - if (list_empty(&event->group_entry)) + /* + * We can have double detach due to exit/hot-unplug + close. + */ + if (!(event->attach_state & PERF_ATTACH_CONTEXT)) return; + + event->attach_state &= ~PERF_ATTACH_CONTEXT; + ctx->nr_events--; if (event->attr.inherit_stat) ctx->nr_stat--; - list_del_init(&event->group_entry); list_del_rcu(&event->event_entry); - if (event->group_leader != event) - event->group_leader->nr_siblings--; + if (event->group_leader == event) + list_del_init(&event->group_entry); - update_event_times(event); + update_group_times(event); /* * If event was in error state, then keep it @@ -348,16 +360,45 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) */ if (event->state > PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_OFF; +} + +static void perf_group_detach(struct perf_event *event) +{ + struct perf_event *sibling, *tmp; + struct list_head *list = NULL; + + /* + * We can have double detach due to exit/hot-unplug + close. + */ + if (!(event->attach_state & PERF_ATTACH_GROUP)) + return; + + event->attach_state &= ~PERF_ATTACH_GROUP; + + /* + * If this is a sibling, remove it from its group. + */ + if (event->group_leader != event) { + list_del_init(&event->group_entry); + event->group_leader->nr_siblings--; + return; + } + + if (!list_empty(&event->group_entry)) + list = &event->group_entry; /* * If this was a group event with sibling events then * upgrade the siblings to singleton events by adding them - * to the context list directly: + * to whatever list we are on. */ list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { - - list_move_tail(&sibling->group_entry, &ctx->group_list); + if (list) + list_move_tail(&sibling->group_entry, list); sibling->group_leader = sibling; + + /* Inherit group flags from the previous leader */ + sibling->group_flags = event->group_flags; } } @@ -508,18 +549,6 @@ retry: } /* - * Update total_time_enabled and total_time_running for all events in a group. - */ -static void update_group_times(struct perf_event *leader) -{ - struct perf_event *event; - - update_event_times(leader); - list_for_each_entry(event, &leader->sibling_list, group_entry) - update_event_times(event); -} - -/* * Cross CPU call to disable a performance event */ static void __perf_event_disable(void *info) @@ -608,14 +637,13 @@ void perf_event_disable(struct perf_event *event) static int event_sched_in(struct perf_event *event, struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx, - int cpu) + struct perf_event_context *ctx) { if (event->state <= PERF_EVENT_STATE_OFF) return 0; event->state = PERF_EVENT_STATE_ACTIVE; - event->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ + event->oncpu = smp_processor_id(); /* * The new state must be visible before we turn it on in the hardware: */ @@ -642,33 +670,47 @@ event_sched_in(struct perf_event *event, static int group_sched_in(struct perf_event *group_event, struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx, - int cpu) + struct perf_event_context *ctx) { - struct perf_event *event, *partial_group; + struct perf_event *event, *partial_group = NULL; + const struct pmu *pmu = group_event->pmu; + bool txn = false; int ret; if (group_event->state == PERF_EVENT_STATE_OFF) return 0; - ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu); - if (ret) - return ret < 0 ? ret : 0; + /* Check if group transaction availabe */ + if (pmu->start_txn) + txn = true; - if (event_sched_in(group_event, cpuctx, ctx, cpu)) + if (txn) + pmu->start_txn(pmu); + + if (event_sched_in(group_event, cpuctx, ctx)) { + if (txn) + pmu->cancel_txn(pmu); return -EAGAIN; + } /* * Schedule in siblings as one group (if any): */ list_for_each_entry(event, &group_event->sibling_list, group_entry) { - if (event_sched_in(event, cpuctx, ctx, cpu)) { + if (event_sched_in(event, cpuctx, ctx)) { partial_group = event; goto group_error; } } - return 0; + if (!txn) + return 0; + + ret = pmu->commit_txn(pmu); + if (!ret) { + pmu->cancel_txn(pmu); + return 0; + } group_error: /* @@ -682,25 +724,10 @@ group_error: } event_sched_out(group_event, cpuctx, ctx); - return -EAGAIN; -} - -/* - * Return 1 for a group consisting entirely of software events, - * 0 if the group contains any hardware events. - */ -static int is_software_only_group(struct perf_event *leader) -{ - struct perf_event *event; - - if (!is_software_event(leader)) - return 0; - - list_for_each_entry(event, &leader->sibling_list, group_entry) - if (!is_software_event(event)) - return 0; + if (txn) + pmu->cancel_txn(pmu); - return 1; + return -EAGAIN; } /* @@ -713,7 +740,7 @@ static int group_can_go_on(struct perf_event *event, /* * Groups consisting entirely of software events can always go on. */ - if (is_software_only_group(event)) + if (event->group_flags & PERF_GROUP_SOFTWARE) return 1; /* * If an exclusive group is already on, no other hardware @@ -738,6 +765,7 @@ static void add_event_to_ctx(struct perf_event *event, struct perf_event_context *ctx) { list_add_event(event, ctx); + perf_group_attach(event); event->tstamp_enabled = ctx->time; event->tstamp_running = ctx->time; event->tstamp_stopped = ctx->time; @@ -754,7 +782,6 @@ static void __perf_install_in_context(void *info) struct perf_event *event = info; struct perf_event_context *ctx = event->ctx; struct perf_event *leader = event->group_leader; - int cpu = smp_processor_id(); int err; /* @@ -801,7 +828,7 @@ static void __perf_install_in_context(void *info) if (!group_can_go_on(event, cpuctx, 1)) err = -EEXIST; else - err = event_sched_in(event, cpuctx, ctx, cpu); + err = event_sched_in(event, cpuctx, ctx); if (err) { /* @@ -943,11 +970,9 @@ static void __perf_event_enable(void *info) } else { perf_disable(); if (event == leader) - err = group_sched_in(event, cpuctx, ctx, - smp_processor_id()); + err = group_sched_in(event, cpuctx, ctx); else - err = event_sched_in(event, cpuctx, ctx, - smp_processor_id()); + err = event_sched_in(event, cpuctx, ctx); perf_enable(); } @@ -1043,8 +1068,15 @@ static int perf_event_refresh(struct perf_event *event, int refresh) return 0; } -void __perf_event_sched_out(struct perf_event_context *ctx, - struct perf_cpu_context *cpuctx) +enum event_type_t { + EVENT_FLEXIBLE = 0x1, + EVENT_PINNED = 0x2, + EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, +}; + +static void ctx_sched_out(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx, + enum event_type_t event_type) { struct perf_event *event; @@ -1055,10 +1087,18 @@ void __perf_event_sched_out(struct perf_event_context *ctx, update_context_time(ctx); perf_disable(); - if (ctx->nr_active) { - list_for_each_entry(event, &ctx->group_list, group_entry) + if (!ctx->nr_active) + goto out_enable; + + if (event_type & EVENT_PINNED) + list_for_each_entry(event, &ctx->pinned_groups, group_entry) group_sched_out(event, cpuctx, ctx); - } + + if (event_type & EVENT_FLEXIBLE) + list_for_each_entry(event, &ctx->flexible_groups, group_entry) + group_sched_out(event, cpuctx, ctx); + + out_enable: perf_enable(); out: raw_spin_unlock(&ctx->lock); @@ -1170,17 +1210,15 @@ static void perf_event_sync_stat(struct perf_event_context *ctx, * not restart the event. */ void perf_event_task_sched_out(struct task_struct *task, - struct task_struct *next, int cpu) + struct task_struct *next) { - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_event_context *ctx = task->perf_event_ctxp; struct perf_event_context *next_ctx; struct perf_event_context *parent; - struct pt_regs *regs; int do_switch = 1; - regs = task_pt_regs(task); - perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); + perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0); if (likely(!ctx || !cpuctx->task_ctx)) return; @@ -1220,15 +1258,13 @@ void perf_event_task_sched_out(struct task_struct *task, rcu_read_unlock(); if (do_switch) { - __perf_event_sched_out(ctx, cpuctx); + ctx_sched_out(ctx, cpuctx, EVENT_ALL); cpuctx->task_ctx = NULL; } } -/* - * Called with IRQs disabled - */ -static void __perf_event_task_sched_out(struct perf_event_context *ctx) +static void task_ctx_sched_out(struct perf_event_context *ctx, + enum event_type_t event_type) { struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); @@ -1238,47 +1274,41 @@ static void __perf_event_task_sched_out(struct perf_event_context *ctx) if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) return; - __perf_event_sched_out(ctx, cpuctx); + ctx_sched_out(ctx, cpuctx, event_type); cpuctx->task_ctx = NULL; } /* * Called with IRQs disabled */ -static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx) +static void __perf_event_task_sched_out(struct perf_event_context *ctx) { - __perf_event_sched_out(&cpuctx->ctx, cpuctx); + task_ctx_sched_out(ctx, EVENT_ALL); +} + +/* + * Called with IRQs disabled + */ +static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, + enum event_type_t event_type) +{ + ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); } static void -__perf_event_sched_in(struct perf_event_context *ctx, - struct perf_cpu_context *cpuctx, int cpu) +ctx_pinned_sched_in(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx) { struct perf_event *event; - int can_add_hw = 1; - - raw_spin_lock(&ctx->lock); - ctx->is_active = 1; - if (likely(!ctx->nr_events)) - goto out; - - ctx->timestamp = perf_clock(); - perf_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(event, &ctx->group_list, group_entry) { - if (event->state <= PERF_EVENT_STATE_OFF || - !event->attr.pinned) + list_for_each_entry(event, &ctx->pinned_groups, group_entry) { + if (event->state <= PERF_EVENT_STATE_OFF) continue; - if (event->cpu != -1 && event->cpu != cpu) + if (event->cpu != -1 && event->cpu != smp_processor_id()) continue; if (group_can_go_on(event, cpuctx, 1)) - group_sched_in(event, cpuctx, ctx, cpu); + group_sched_in(event, cpuctx, ctx); /* * If this pinned group hasn't been scheduled, @@ -1289,32 +1319,83 @@ __perf_event_sched_in(struct perf_event_context *ctx, event->state = PERF_EVENT_STATE_ERROR; } } +} - list_for_each_entry(event, &ctx->group_list, group_entry) { - /* - * Ignore events in OFF or ERROR state, and - * ignore pinned events since we did them already. - */ - if (event->state <= PERF_EVENT_STATE_OFF || - event->attr.pinned) - continue; +static void +ctx_flexible_sched_in(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx) +{ + struct perf_event *event; + int can_add_hw = 1; + list_for_each_entry(event, &ctx->flexible_groups, group_entry) { + /* Ignore events in OFF or ERROR state */ + if (event->state <= PERF_EVENT_STATE_OFF) + continue; /* * Listen to the 'cpu' scheduling filter constraint * of events: */ - if (event->cpu != -1 && event->cpu != cpu) + if (event->cpu != -1 && event->cpu != smp_processor_id()) continue; if (group_can_go_on(event, cpuctx, can_add_hw)) - if (group_sched_in(event, cpuctx, ctx, cpu)) + if (group_sched_in(event, cpuctx, ctx)) can_add_hw = 0; } +} + +static void +ctx_sched_in(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx, + enum event_type_t event_type) +{ + raw_spin_lock(&ctx->lock); + ctx->is_active = 1; + if (likely(!ctx->nr_events)) + goto out; + + ctx->timestamp = perf_clock(); + + perf_disable(); + + /* + * First go through the list and put on any pinned groups + * in order to give them the best chance of going on. + */ + if (event_type & EVENT_PINNED) + ctx_pinned_sched_in(ctx, cpuctx); + + /* Then walk through the lower prio flexible groups */ + if (event_type & EVENT_FLEXIBLE) + ctx_flexible_sched_in(ctx, cpuctx); + perf_enable(); out: raw_spin_unlock(&ctx->lock); } +static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, + enum event_type_t event_type) +{ + struct perf_event_context *ctx = &cpuctx->ctx; + + ctx_sched_in(ctx, cpuctx, event_type); +} + +static void task_ctx_sched_in(struct task_struct *task, + enum event_type_t event_type) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = task->perf_event_ctxp; + + if (likely(!ctx)) + return; + if (cpuctx->task_ctx == ctx) + return; + ctx_sched_in(ctx, cpuctx, event_type); + cpuctx->task_ctx = ctx; +} /* * Called from scheduler to add the events of the current task * with interrupts disabled. @@ -1326,38 +1407,135 @@ __perf_event_sched_in(struct perf_event_context *ctx, * accessing the event control register. If a NMI hits, then it will * keep the event running. */ -void perf_event_task_sched_in(struct task_struct *task, int cpu) +void perf_event_task_sched_in(struct task_struct *task) { - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_event_context *ctx = task->perf_event_ctxp; if (likely(!ctx)) return; + if (cpuctx->task_ctx == ctx) return; - __perf_event_sched_in(ctx, cpuctx, cpu); + + perf_disable(); + + /* + * We want to keep the following priority order: + * cpu pinned (that don't need to move), task pinned, + * cpu flexible, task flexible. + */ + cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); + + ctx_sched_in(ctx, cpuctx, EVENT_PINNED); + cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE); + ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE); + cpuctx->task_ctx = ctx; + + perf_enable(); } -static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) +#define MAX_INTERRUPTS (~0ULL) + +static void perf_log_throttle(struct perf_event *event, int enable); + +static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) { - struct perf_event_context *ctx = &cpuctx->ctx; + u64 frequency = event->attr.sample_freq; + u64 sec = NSEC_PER_SEC; + u64 divisor, dividend; - __perf_event_sched_in(ctx, cpuctx, cpu); + int count_fls, nsec_fls, frequency_fls, sec_fls; + + count_fls = fls64(count); + nsec_fls = fls64(nsec); + frequency_fls = fls64(frequency); + sec_fls = 30; + + /* + * We got @count in @nsec, with a target of sample_freq HZ + * the target period becomes: + * + * @count * 10^9 + * period = ------------------- + * @nsec * sample_freq + * + */ + + /* + * Reduce accuracy by one bit such that @a and @b converge + * to a similar magnitude. + */ +#define REDUCE_FLS(a, b) \ +do { \ + if (a##_fls > b##_fls) { \ + a >>= 1; \ + a##_fls--; \ + } else { \ + b >>= 1; \ + b##_fls--; \ + } \ +} while (0) + + /* + * Reduce accuracy until either term fits in a u64, then proceed with + * the other, so that finally we can do a u64/u64 division. + */ + while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { + REDUCE_FLS(nsec, frequency); + REDUCE_FLS(sec, count); + } + + if (count_fls + sec_fls > 64) { + divisor = nsec * frequency; + + while (count_fls + sec_fls > 64) { + REDUCE_FLS(count, sec); + divisor >>= 1; + } + + dividend = count * sec; + } else { + dividend = count * sec; + + while (nsec_fls + frequency_fls > 64) { + REDUCE_FLS(nsec, frequency); + dividend >>= 1; + } + + divisor = nsec * frequency; + } + + if (!divisor) + return dividend; + + return div64_u64(dividend, divisor); } -#define MAX_INTERRUPTS (~0ULL) +static void perf_event_stop(struct perf_event *event) +{ + if (!event->pmu->stop) + return event->pmu->disable(event); -static void perf_log_throttle(struct perf_event *event, int enable); + return event->pmu->stop(event); +} + +static int perf_event_start(struct perf_event *event) +{ + if (!event->pmu->start) + return event->pmu->enable(event); + + return event->pmu->start(event); +} -static void perf_adjust_period(struct perf_event *event, u64 events) +static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) { struct hw_perf_event *hwc = &event->hw; - u64 period, sample_period; + s64 period, sample_period; s64 delta; - events *= hwc->sample_period; - period = div64_u64(events, event->attr.sample_freq); + period = perf_calculate_period(event, nsec, count); delta = (s64)(period - hwc->sample_period); delta = (delta + 7) / 8; /* low pass filter */ @@ -1368,13 +1546,22 @@ static void perf_adjust_period(struct perf_event *event, u64 events) sample_period = 1; hwc->sample_period = sample_period; + + if (atomic64_read(&hwc->period_left) > 8*sample_period) { + perf_disable(); + perf_event_stop(event); + atomic64_set(&hwc->period_left, 0); + perf_event_start(event); + perf_enable(); + } } static void perf_ctx_adjust_freq(struct perf_event_context *ctx) { struct perf_event *event; struct hw_perf_event *hwc; - u64 interrupts, freq; + u64 interrupts, now; + s64 delta; raw_spin_lock(&ctx->lock); list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { @@ -1394,45 +1581,23 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx) */ if (interrupts == MAX_INTERRUPTS) { perf_log_throttle(event, 1); + perf_disable(); event->pmu->unthrottle(event); - interrupts = 2*sysctl_perf_event_sample_rate/HZ; + perf_enable(); } if (!event->attr.freq || !event->attr.sample_freq) continue; - /* - * if the specified freq < HZ then we need to skip ticks - */ - if (event->attr.sample_freq < HZ) { - freq = event->attr.sample_freq; - - hwc->freq_count += freq; - hwc->freq_interrupts += interrupts; - - if (hwc->freq_count < HZ) - continue; - - interrupts = hwc->freq_interrupts; - hwc->freq_interrupts = 0; - hwc->freq_count -= HZ; - } else - freq = HZ; - - perf_adjust_period(event, freq * interrupts); + perf_disable(); + event->pmu->read(event); + now = atomic64_read(&event->count); + delta = now - hwc->freq_count_stamp; + hwc->freq_count_stamp = now; - /* - * In order to avoid being stalled by an (accidental) huge - * sample period, force reset the sample period if we didn't - * get any events in this freq period. - */ - if (!interrupts) { - perf_disable(); - event->pmu->disable(event); - atomic64_set(&hwc->period_left, 0); - event->pmu->enable(event); - perf_enable(); - } + if (delta > 0) + perf_adjust_period(event, TICK_NSEC, delta); + perf_enable(); } raw_spin_unlock(&ctx->lock); } @@ -1442,51 +1607,67 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx) */ static void rotate_ctx(struct perf_event_context *ctx) { - struct perf_event *event; - - if (!ctx->nr_events) - return; - raw_spin_lock(&ctx->lock); - /* - * Rotate the first entry last (works just fine for group events too): - */ - perf_disable(); - list_for_each_entry(event, &ctx->group_list, group_entry) { - list_move_tail(&event->group_entry, &ctx->group_list); - break; - } - perf_enable(); + + /* Rotate the first entry last of non-pinned groups */ + list_rotate_left(&ctx->flexible_groups); raw_spin_unlock(&ctx->lock); } -void perf_event_task_tick(struct task_struct *curr, int cpu) +void perf_event_task_tick(struct task_struct *curr) { struct perf_cpu_context *cpuctx; struct perf_event_context *ctx; + int rotate = 0; if (!atomic_read(&nr_events)) return; - cpuctx = &per_cpu(perf_cpu_context, cpu); + cpuctx = &__get_cpu_var(perf_cpu_context); + if (cpuctx->ctx.nr_events && + cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) + rotate = 1; + ctx = curr->perf_event_ctxp; + if (ctx && ctx->nr_events && ctx->nr_events != ctx->nr_active) + rotate = 1; perf_ctx_adjust_freq(&cpuctx->ctx); if (ctx) perf_ctx_adjust_freq(ctx); - perf_event_cpu_sched_out(cpuctx); + if (!rotate) + return; + + perf_disable(); + cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); if (ctx) - __perf_event_task_sched_out(ctx); + task_ctx_sched_out(ctx, EVENT_FLEXIBLE); rotate_ctx(&cpuctx->ctx); if (ctx) rotate_ctx(ctx); - perf_event_cpu_sched_in(cpuctx, cpu); + cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE); if (ctx) - perf_event_task_sched_in(curr, cpu); + task_ctx_sched_in(curr, EVENT_FLEXIBLE); + perf_enable(); +} + +static int event_enable_on_exec(struct perf_event *event, + struct perf_event_context *ctx) +{ + if (!event->attr.enable_on_exec) + return 0; + + event->attr.enable_on_exec = 0; + if (event->state >= PERF_EVENT_STATE_INACTIVE) + return 0; + + __perf_event_mark_enabled(event, ctx); + + return 1; } /* @@ -1499,6 +1680,7 @@ static void perf_event_enable_on_exec(struct task_struct *task) struct perf_event *event; unsigned long flags; int enabled = 0; + int ret; local_irq_save(flags); ctx = task->perf_event_ctxp; @@ -1509,14 +1691,16 @@ static void perf_event_enable_on_exec(struct task_struct *task) raw_spin_lock(&ctx->lock); - list_for_each_entry(event, &ctx->group_list, group_entry) { - if (!event->attr.enable_on_exec) - continue; - event->attr.enable_on_exec = 0; - if (event->state >= PERF_EVENT_STATE_INACTIVE) - continue; - __perf_event_mark_enabled(event, ctx); - enabled = 1; + list_for_each_entry(event, &ctx->pinned_groups, group_entry) { + ret = event_enable_on_exec(event, ctx); + if (ret) + enabled = 1; + } + + list_for_each_entry(event, &ctx->flexible_groups, group_entry) { + ret = event_enable_on_exec(event, ctx); + if (ret) + enabled = 1; } /* @@ -1527,7 +1711,7 @@ static void perf_event_enable_on_exec(struct task_struct *task) raw_spin_unlock(&ctx->lock); - perf_event_task_sched_in(task, smp_processor_id()); + perf_event_task_sched_in(task); out: local_irq_restore(flags); } @@ -1590,7 +1774,8 @@ __perf_event_init_context(struct perf_event_context *ctx, { raw_spin_lock_init(&ctx->lock); mutex_init(&ctx->mutex); - INIT_LIST_HEAD(&ctx->group_list); + INIT_LIST_HEAD(&ctx->pinned_groups); + INIT_LIST_HEAD(&ctx->flexible_groups); INIT_LIST_HEAD(&ctx->event_list); atomic_set(&ctx->refcount, 1); ctx->task = task; @@ -1698,6 +1883,7 @@ static void free_event_rcu(struct rcu_head *head) } static void perf_pending_sync(struct perf_event *event); +static void perf_mmap_data_put(struct perf_mmap_data *data); static void free_event(struct perf_event *event) { @@ -1713,9 +1899,9 @@ static void free_event(struct perf_event *event) atomic_dec(&nr_task_events); } - if (event->output) { - fput(event->output->filp); - event->output = NULL; + if (event->data) { + perf_mmap_data_put(event->data); + event->data = NULL; } if (event->destroy) @@ -1729,9 +1915,30 @@ int perf_event_release_kernel(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; + /* + * Remove from the PMU, can't get re-enabled since we got + * here because the last ref went. + */ + perf_event_disable(event); + WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_event_remove_from_context(event); + /* + * There are two ways this annotation is useful: + * + * 1) there is a lock recursion from perf_event_exit_task + * see the comment there. + * + * 2) there is a lock-inversion with mmap_sem through + * perf_event_read_group(), which takes faults while + * holding ctx->mutex, however this is called after + * the last filedesc died, so there is no possibility + * to trigger the AB-BA case. + */ + mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); + raw_spin_lock_irq(&ctx->lock); + perf_group_detach(event); + list_del_event(event, ctx); + raw_spin_unlock_irq(&ctx->lock); mutex_unlock(&ctx->mutex); mutex_lock(&event->owner->perf_event_mutex); @@ -2011,7 +2218,27 @@ unlock: return ret; } -static int perf_event_set_output(struct perf_event *event, int output_fd); +static const struct file_operations perf_fops; + +static struct perf_event *perf_fget_light(int fd, int *fput_needed) +{ + struct file *file; + + file = fget_light(fd, fput_needed); + if (!file) + return ERR_PTR(-EBADF); + + if (file->f_op != &perf_fops) { + fput_light(file, *fput_needed); + *fput_needed = 0; + return ERR_PTR(-EBADF); + } + + return file->private_data; +} + +static int perf_event_set_output(struct perf_event *event, + struct perf_event *output_event); static int perf_event_set_filter(struct perf_event *event, void __user *arg); static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) @@ -2038,7 +2265,23 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return perf_event_period(event, (u64 __user *)arg); case PERF_EVENT_IOC_SET_OUTPUT: - return perf_event_set_output(event, arg); + { + struct perf_event *output_event = NULL; + int fput_needed = 0; + int ret; + + if (arg != -1) { + output_event = perf_fget_light(arg, &fput_needed); + if (IS_ERR(output_event)) + return PTR_ERR(output_event); + } + + ret = perf_event_set_output(event, output_event); + if (output_event) + fput_light(output_event->filp, fput_needed); + + return ret; + } case PERF_EVENT_IOC_SET_FILTER: return perf_event_set_filter(event, (void __user *)arg); @@ -2133,11 +2376,6 @@ unlock: rcu_read_unlock(); } -static unsigned long perf_data_size(struct perf_mmap_data *data) -{ - return data->nr_pages << (PAGE_SHIFT + data->data_order); -} - #ifndef CONFIG_PERF_USE_VMALLOC /* @@ -2156,6 +2394,19 @@ perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff) return virt_to_page(data->data_pages[pgoff - 1]); } +static void *perf_mmap_alloc_page(int cpu) +{ + struct page *page; + int node; + + node = (cpu == -1) ? cpu : cpu_to_node(cpu); + page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); + if (!page) + return NULL; + + return page_address(page); +} + static struct perf_mmap_data * perf_mmap_data_alloc(struct perf_event *event, int nr_pages) { @@ -2163,8 +2414,6 @@ perf_mmap_data_alloc(struct perf_event *event, int nr_pages) unsigned long size; int i; - WARN_ON(atomic_read(&event->mmap_count)); - size = sizeof(struct perf_mmap_data); size += nr_pages * sizeof(void *); @@ -2172,17 +2421,16 @@ perf_mmap_data_alloc(struct perf_event *event, int nr_pages) if (!data) goto fail; - data->user_page = (void *)get_zeroed_page(GFP_KERNEL); + data->user_page = perf_mmap_alloc_page(event->cpu); if (!data->user_page) goto fail_user_page; for (i = 0; i < nr_pages; i++) { - data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); + data->data_pages[i] = perf_mmap_alloc_page(event->cpu); if (!data->data_pages[i]) goto fail_data_pages; } - data->data_order = 0; data->nr_pages = nr_pages; return data; @@ -2218,6 +2466,11 @@ static void perf_mmap_data_free(struct perf_mmap_data *data) kfree(data); } +static inline int page_order(struct perf_mmap_data *data) +{ + return 0; +} + #else /* @@ -2226,10 +2479,15 @@ static void perf_mmap_data_free(struct perf_mmap_data *data) * Required for architectures that have d-cache aliasing issues. */ +static inline int page_order(struct perf_mmap_data *data) +{ + return data->page_order; +} + static struct page * perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff) { - if (pgoff > (1UL << data->data_order)) + if (pgoff > (1UL << page_order(data))) return NULL; return vmalloc_to_page((void *)data->user_page + pgoff * PAGE_SIZE); @@ -2249,7 +2507,7 @@ static void perf_mmap_data_free_work(struct work_struct *work) int i, nr; data = container_of(work, struct perf_mmap_data, work); - nr = 1 << data->data_order; + nr = 1 << page_order(data); base = data->user_page; for (i = 0; i < nr + 1; i++) @@ -2271,8 +2529,6 @@ perf_mmap_data_alloc(struct perf_event *event, int nr_pages) unsigned long size; void *all_buf; - WARN_ON(atomic_read(&event->mmap_count)); - size = sizeof(struct perf_mmap_data); size += sizeof(void *); @@ -2288,7 +2544,7 @@ perf_mmap_data_alloc(struct perf_event *event, int nr_pages) data->user_page = all_buf; data->data_pages[0] = all_buf + PAGE_SIZE; - data->data_order = ilog2(nr_pages); + data->page_order = ilog2(nr_pages); data->nr_pages = 1; return data; @@ -2302,6 +2558,11 @@ fail: #endif +static unsigned long perf_data_size(struct perf_mmap_data *data) +{ + return data->nr_pages << (PAGE_SHIFT + page_order(data)); +} + static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct perf_event *event = vma->vm_file->private_data; @@ -2342,8 +2603,6 @@ perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data) { long max_size = perf_data_size(data); - atomic_set(&data->lock, -1); - if (event->attr.watermark) { data->watermark = min_t(long, max_size, event->attr.wakeup_watermark); @@ -2352,7 +2611,7 @@ perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data) if (!data->watermark) data->watermark = max_size / 2; - + atomic_set(&data->refcount, 1); rcu_assign_pointer(event->data, data); } @@ -2364,13 +2623,26 @@ static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head) perf_mmap_data_free(data); } -static void perf_mmap_data_release(struct perf_event *event) +static struct perf_mmap_data *perf_mmap_data_get(struct perf_event *event) { - struct perf_mmap_data *data = event->data; + struct perf_mmap_data *data; + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (data) { + if (!atomic_inc_not_zero(&data->refcount)) + data = NULL; + } + rcu_read_unlock(); + + return data; +} - WARN_ON(atomic_read(&event->mmap_count)); +static void perf_mmap_data_put(struct perf_mmap_data *data) +{ + if (!atomic_dec_and_test(&data->refcount)) + return; - rcu_assign_pointer(event->data, NULL); call_rcu(&data->rcu_head, perf_mmap_data_free_rcu); } @@ -2385,15 +2657,18 @@ static void perf_mmap_close(struct vm_area_struct *vma) { struct perf_event *event = vma->vm_file->private_data; - WARN_ON_ONCE(event->ctx->parent_ctx); if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) { unsigned long size = perf_data_size(event->data); - struct user_struct *user = current_user(); + struct user_struct *user = event->mmap_user; + struct perf_mmap_data *data = event->data; atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm); - vma->vm_mm->locked_vm -= event->data->nr_locked; - perf_mmap_data_release(event); + vma->vm_mm->locked_vm -= event->mmap_locked; + rcu_assign_pointer(event->data, NULL); mutex_unlock(&event->mmap_mutex); + + perf_mmap_data_put(data); + free_uid(user); } } @@ -2416,6 +2691,14 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) long user_extra, extra; int ret = 0; + /* + * Don't allow mmap() of inherited per-task counters. This would + * create a performance issue due to all children writing to the + * same buffer. + */ + if (event->cpu == -1 && event->attr.inherit) + return -EINVAL; + if (!(vma->vm_flags & VM_SHARED)) return -EINVAL; @@ -2437,13 +2720,10 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) WARN_ON_ONCE(event->ctx->parent_ctx); mutex_lock(&event->mmap_mutex); - if (event->output) { - ret = -EINVAL; - goto unlock; - } - - if (atomic_inc_not_zero(&event->mmap_count)) { - if (nr_pages != event->data->nr_pages) + if (event->data) { + if (event->data->nr_pages == nr_pages) + atomic_inc(&event->data->refcount); + else ret = -EINVAL; goto unlock; } @@ -2462,7 +2742,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) if (user_locked > user_lock_limit) extra = user_locked - user_lock_limit; - lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; + lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; locked = vma->vm_mm->locked_vm + extra; @@ -2475,21 +2755,23 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) WARN_ON(event->data); data = perf_mmap_data_alloc(event, nr_pages); - ret = -ENOMEM; - if (!data) + if (!data) { + ret = -ENOMEM; goto unlock; + } - ret = 0; perf_mmap_data_init(event, data); - - atomic_set(&event->mmap_count, 1); - atomic_long_add(user_extra, &user->locked_vm); - vma->vm_mm->locked_vm += extra; - event->data->nr_locked = extra; if (vma->vm_flags & VM_WRITE) event->data->writable = 1; + atomic_long_add(user_extra, &user->locked_vm); + event->mmap_locked = extra; + event->mmap_user = get_current_user(); + vma->vm_mm->locked_vm += event->mmap_locked; + unlock: + if (!ret) + atomic_inc(&event->mmap_count); mutex_unlock(&event->mmap_mutex); vma->vm_flags |= VM_RESERVED; @@ -2515,6 +2797,7 @@ static int perf_fasync(int fd, struct file *filp, int on) } static const struct file_operations perf_fops = { + .llseek = no_llseek, .release = perf_release, .read = perf_read, .poll = perf_poll, @@ -2658,6 +2941,33 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) return NULL; } +__weak +void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip) +{ +} + + +/* + * We assume there is only KVM supporting the callbacks. + * Later on, we might change it to a list if there is + * another virtualization implementation supporting the callbacks. + */ +struct perf_guest_info_callbacks *perf_guest_cbs; + +int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = cbs; + return 0; +} +EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); + +int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = NULL; + return 0; +} +EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); + /* * Output */ @@ -2693,127 +3003,87 @@ static void perf_output_wakeup(struct perf_output_handle *handle) } /* - * Curious locking construct. - * * We need to ensure a later event_id doesn't publish a head when a former - * event_id isn't done writing. However since we need to deal with NMIs we + * event isn't done writing. However since we need to deal with NMIs we * cannot fully serialize things. * - * What we do is serialize between CPUs so we only have to deal with NMI - * nesting on a single CPU. - * * We only publish the head (and generate a wakeup) when the outer-most - * event_id completes. + * event completes. */ -static void perf_output_lock(struct perf_output_handle *handle) +static void perf_output_get_handle(struct perf_output_handle *handle) { struct perf_mmap_data *data = handle->data; - int cur, cpu = get_cpu(); - - handle->locked = 0; - for (;;) { - cur = atomic_cmpxchg(&data->lock, -1, cpu); - if (cur == -1) { - handle->locked = 1; - break; - } - if (cur == cpu) - break; - - cpu_relax(); - } + preempt_disable(); + local_inc(&data->nest); + handle->wakeup = local_read(&data->wakeup); } -static void perf_output_unlock(struct perf_output_handle *handle) +static void perf_output_put_handle(struct perf_output_handle *handle) { struct perf_mmap_data *data = handle->data; unsigned long head; - int cpu; - - data->done_head = data->head; - - if (!handle->locked) - goto out; again: - /* - * The xchg implies a full barrier that ensures all writes are done - * before we publish the new head, matched by a rmb() in userspace when - * reading this position. - */ - while ((head = atomic_long_xchg(&data->done_head, 0))) - data->user_page->data_head = head; + head = local_read(&data->head); /* - * NMI can happen here, which means we can miss a done_head update. + * IRQ/NMI can happen here, which means we can miss a head update. */ - cpu = atomic_xchg(&data->lock, -1); - WARN_ON_ONCE(cpu != smp_processor_id()); + if (!local_dec_and_test(&data->nest)) + goto out; /* - * Therefore we have to validate we did not indeed do so. + * Publish the known good head. Rely on the full barrier implied + * by atomic_dec_and_test() order the data->head read and this + * write. */ - if (unlikely(atomic_long_read(&data->done_head))) { - /* - * Since we had it locked, we can lock it again. - */ - while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) - cpu_relax(); + data->user_page->data_head = head; + /* + * Now check if we missed an update, rely on the (compiler) + * barrier in atomic_dec_and_test() to re-read data->head. + */ + if (unlikely(head != local_read(&data->head))) { + local_inc(&data->nest); goto again; } - if (atomic_xchg(&data->wakeup, 0)) + if (handle->wakeup != local_read(&data->wakeup)) perf_output_wakeup(handle); -out: - put_cpu(); + + out: + preempt_enable(); } -void perf_output_copy(struct perf_output_handle *handle, +__always_inline void perf_output_copy(struct perf_output_handle *handle, const void *buf, unsigned int len) { - unsigned int pages_mask; - unsigned long offset; - unsigned int size; - void **pages; - - offset = handle->offset; - pages_mask = handle->data->nr_pages - 1; - pages = handle->data->data_pages; - do { - unsigned long page_offset; - unsigned long page_size; - int nr; + unsigned long size = min_t(unsigned long, handle->size, len); - nr = (offset >> PAGE_SHIFT) & pages_mask; - page_size = 1UL << (handle->data->data_order + PAGE_SHIFT); - page_offset = offset & (page_size - 1); - size = min_t(unsigned int, page_size - page_offset, len); + memcpy(handle->addr, buf, size); - memcpy(pages[nr] + page_offset, buf, size); + len -= size; + handle->addr += size; + buf += size; + handle->size -= size; + if (!handle->size) { + struct perf_mmap_data *data = handle->data; - len -= size; - buf += size; - offset += size; + handle->page++; + handle->page &= data->nr_pages - 1; + handle->addr = data->data_pages[handle->page]; + handle->size = PAGE_SIZE << page_order(data); + } } while (len); - - handle->offset = offset; - - /* - * Check we didn't copy past our reservation window, taking the - * possible unsigned int wrap into account. - */ - WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); } int perf_output_begin(struct perf_output_handle *handle, struct perf_event *event, unsigned int size, int nmi, int sample) { - struct perf_event *output_event; struct perf_mmap_data *data; unsigned long tail, offset, head; int have_lost; @@ -2830,10 +3100,6 @@ int perf_output_begin(struct perf_output_handle *handle, if (event->parent) event = event->parent; - output_event = rcu_dereference(event->output); - if (output_event) - event = output_event; - data = rcu_dereference(event->data); if (!data) goto out; @@ -2844,13 +3110,13 @@ int perf_output_begin(struct perf_output_handle *handle, handle->sample = sample; if (!data->nr_pages) - goto fail; + goto out; - have_lost = atomic_read(&data->lost); + have_lost = local_read(&data->lost); if (have_lost) size += sizeof(lost_event); - perf_output_lock(handle); + perf_output_get_handle(handle); do { /* @@ -2860,24 +3126,28 @@ int perf_output_begin(struct perf_output_handle *handle, */ tail = ACCESS_ONCE(data->user_page->data_tail); smp_rmb(); - offset = head = atomic_long_read(&data->head); + offset = head = local_read(&data->head); head += size; if (unlikely(!perf_output_space(data, tail, offset, head))) goto fail; - } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); + } while (local_cmpxchg(&data->head, offset, head) != offset); - handle->offset = offset; - handle->head = head; + if (head - local_read(&data->wakeup) > data->watermark) + local_add(data->watermark, &data->wakeup); - if (head - tail > data->watermark) - atomic_set(&data->wakeup, 1); + handle->page = offset >> (PAGE_SHIFT + page_order(data)); + handle->page &= data->nr_pages - 1; + handle->size = offset & ((PAGE_SIZE << page_order(data)) - 1); + handle->addr = data->data_pages[handle->page]; + handle->addr += handle->size; + handle->size = (PAGE_SIZE << page_order(data)) - handle->size; if (have_lost) { lost_event.header.type = PERF_RECORD_LOST; lost_event.header.misc = 0; lost_event.header.size = sizeof(lost_event); lost_event.id = event->id; - lost_event.lost = atomic_xchg(&data->lost, 0); + lost_event.lost = local_xchg(&data->lost, 0); perf_output_put(handle, lost_event); } @@ -2885,8 +3155,8 @@ int perf_output_begin(struct perf_output_handle *handle, return 0; fail: - atomic_inc(&data->lost); - perf_output_unlock(handle); + local_inc(&data->lost); + perf_output_put_handle(handle); out: rcu_read_unlock(); @@ -2901,14 +3171,14 @@ void perf_output_end(struct perf_output_handle *handle) int wakeup_events = event->attr.wakeup_events; if (handle->sample && wakeup_events) { - int events = atomic_inc_return(&data->events); + int events = local_inc_return(&data->events); if (events >= wakeup_events) { - atomic_sub(wakeup_events, &data->events); - atomic_set(&data->wakeup, 1); + local_sub(wakeup_events, &data->events); + local_inc(&data->wakeup); } } - perf_output_unlock(handle); + perf_output_put_handle(handle); rcu_read_unlock(); } @@ -3243,9 +3513,8 @@ static void perf_event_task_output(struct perf_event *event, struct perf_task_event *task_event) { struct perf_output_handle handle; - int size; struct task_struct *task = task_event->task; - int ret; + int size, ret; size = task_event->event_id.header.size; ret = perf_output_begin(&handle, event, size, 0, 0); @@ -3259,8 +3528,6 @@ static void perf_event_task_output(struct perf_event *event, task_event->event_id.tid = perf_event_tid(event, task); task_event->event_id.ptid = perf_event_tid(event, current); - task_event->event_id.time = perf_clock(); - perf_output_put(&handle, task_event->event_id); perf_output_end(&handle); @@ -3268,7 +3535,7 @@ static void perf_event_task_output(struct perf_event *event, static int perf_event_task_match(struct perf_event *event) { - if (event->state != PERF_EVENT_STATE_ACTIVE) + if (event->state < PERF_EVENT_STATE_INACTIVE) return 0; if (event->cpu != -1 && event->cpu != smp_processor_id()) @@ -3300,7 +3567,7 @@ static void perf_event_task_event(struct perf_task_event *task_event) cpuctx = &get_cpu_var(perf_cpu_context); perf_event_task_ctx(&cpuctx->ctx, task_event); if (!ctx) - ctx = rcu_dereference(task_event->task->perf_event_ctxp); + ctx = rcu_dereference(current->perf_event_ctxp); if (ctx) perf_event_task_ctx(ctx, task_event); put_cpu_var(perf_cpu_context); @@ -3331,6 +3598,7 @@ static void perf_event_task(struct task_struct *task, /* .ppid */ /* .tid */ /* .ptid */ + .time = perf_clock(), }, }; @@ -3380,7 +3648,7 @@ static void perf_event_comm_output(struct perf_event *event, static int perf_event_comm_match(struct perf_event *event) { - if (event->state != PERF_EVENT_STATE_ACTIVE) + if (event->state < PERF_EVENT_STATE_INACTIVE) return 0; if (event->cpu != -1 && event->cpu != smp_processor_id()) @@ -3500,7 +3768,7 @@ static void perf_event_mmap_output(struct perf_event *event, static int perf_event_mmap_match(struct perf_event *event, struct perf_mmap_event *mmap_event) { - if (event->state != PERF_EVENT_STATE_ACTIVE) + if (event->state < PERF_EVENT_STATE_INACTIVE) return 0; if (event->cpu != -1 && event->cpu != smp_processor_id()) @@ -3602,14 +3870,14 @@ void __perf_event_mmap(struct vm_area_struct *vma) .event_id = { .header = { .type = PERF_RECORD_MMAP, - .misc = 0, + .misc = PERF_RECORD_MISC_USER, /* .size */ }, /* .pid */ /* .tid */ .start = vma->vm_start, .len = vma->vm_end - vma->vm_start, - .pgoff = vma->vm_pgoff, + .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, }, }; @@ -3689,12 +3957,12 @@ static int __perf_event_overflow(struct perf_event *event, int nmi, if (event->attr.freq) { u64 now = perf_clock(); - s64 delta = now - hwc->freq_stamp; + s64 delta = now - hwc->freq_time_stamp; - hwc->freq_stamp = now; + hwc->freq_time_stamp = now; - if (delta > 0 && delta < TICK_NSEC) - perf_adjust_period(event, NSEC_PER_SEC / (int)delta); + if (delta > 0 && delta < 2*TICK_NSEC) + perf_adjust_period(event, delta, hwc->last_period); } /* @@ -3790,13 +4058,6 @@ static void perf_swevent_overflow(struct perf_event *event, u64 overflow, } } -static void perf_swevent_unthrottle(struct perf_event *event) -{ - /* - * Nothing to do, we already reset hwc->interrupts. - */ -} - static void perf_swevent_add(struct perf_event *event, u64 nr, int nmi, struct perf_sample_data *data, struct pt_regs *regs) @@ -3820,39 +4081,6 @@ static void perf_swevent_add(struct perf_event *event, u64 nr, perf_swevent_overflow(event, 0, nmi, data, regs); } -static int perf_swevent_is_counting(struct perf_event *event) -{ - /* - * The event is active, we're good! - */ - if (event->state == PERF_EVENT_STATE_ACTIVE) - return 1; - - /* - * The event is off/error, not counting. - */ - if (event->state != PERF_EVENT_STATE_INACTIVE) - return 0; - - /* - * The event is inactive, if the context is active - * we're part of a group that didn't make it on the 'pmu', - * not counting. - */ - if (event->ctx->is_active) - return 0; - - /* - * We're inactive and the context is too, this means the - * task is scheduled out, we're counting events that happen - * to us, like migration events. - */ - return 1; -} - -static int perf_tp_event_match(struct perf_event *event, - struct perf_sample_data *data); - static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs) { @@ -3873,12 +4101,6 @@ static int perf_swevent_match(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) { - if (event->cpu != -1 && event->cpu != smp_processor_id()) - return 0; - - if (!perf_swevent_is_counting(event)) - return 0; - if (event->attr.type != type) return 0; @@ -3888,30 +4110,88 @@ static int perf_swevent_match(struct perf_event *event, if (perf_exclude_event(event, regs)) return 0; - if (event->attr.type == PERF_TYPE_TRACEPOINT && - !perf_tp_event_match(event, data)) - return 0; - return 1; } -static void perf_swevent_ctx_event(struct perf_event_context *ctx, - enum perf_type_id type, - u32 event_id, u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) +static inline u64 swevent_hash(u64 type, u32 event_id) +{ + u64 val = event_id | (type << 32); + + return hash_64(val, SWEVENT_HLIST_BITS); +} + +static inline struct hlist_head * +__find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id) { + u64 hash = swevent_hash(type, event_id); + + return &hlist->heads[hash]; +} + +/* For the read side: events when they trigger */ +static inline struct hlist_head * +find_swevent_head_rcu(struct perf_cpu_context *ctx, u64 type, u32 event_id) +{ + struct swevent_hlist *hlist; + + hlist = rcu_dereference(ctx->swevent_hlist); + if (!hlist) + return NULL; + + return __find_swevent_head(hlist, type, event_id); +} + +/* For the event head insertion and removal in the hlist */ +static inline struct hlist_head * +find_swevent_head(struct perf_cpu_context *ctx, struct perf_event *event) +{ + struct swevent_hlist *hlist; + u32 event_id = event->attr.config; + u64 type = event->attr.type; + + /* + * Event scheduling is always serialized against hlist allocation + * and release. Which makes the protected version suitable here. + * The context lock guarantees that. + */ + hlist = rcu_dereference_protected(ctx->swevent_hlist, + lockdep_is_held(&event->ctx->lock)); + if (!hlist) + return NULL; + + return __find_swevent_head(hlist, type, event_id); +} + +static void do_perf_sw_event(enum perf_type_id type, u32 event_id, + u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_cpu_context *cpuctx; struct perf_event *event; + struct hlist_node *node; + struct hlist_head *head; - list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + cpuctx = &__get_cpu_var(perf_cpu_context); + + rcu_read_lock(); + + head = find_swevent_head_rcu(cpuctx, type, event_id); + + if (!head) + goto end; + + hlist_for_each_entry_rcu(event, node, head, hlist_entry) { if (perf_swevent_match(event, type, event_id, data, regs)) perf_swevent_add(event, nr, nmi, data, regs); } +end: + rcu_read_unlock(); } int perf_swevent_get_recursion_context(void) { - struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); int rctx; if (in_nmi()) @@ -3923,10 +4203,8 @@ int perf_swevent_get_recursion_context(void) else rctx = 0; - if (cpuctx->recursion[rctx]) { - put_cpu_var(perf_cpu_context); + if (cpuctx->recursion[rctx]) return -1; - } cpuctx->recursion[rctx]++; barrier(); @@ -3940,31 +4218,9 @@ void perf_swevent_put_recursion_context(int rctx) struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); barrier(); cpuctx->recursion[rctx]--; - put_cpu_var(perf_cpu_context); } EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context); -static void do_perf_sw_event(enum perf_type_id type, u32 event_id, - u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct perf_cpu_context *cpuctx; - struct perf_event_context *ctx; - - cpuctx = &__get_cpu_var(perf_cpu_context); - rcu_read_lock(); - perf_swevent_ctx_event(&cpuctx->ctx, type, event_id, - nr, nmi, data, regs); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_event_ctxp); - if (ctx) - perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs); - rcu_read_unlock(); -} void __perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) @@ -3972,16 +4228,17 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi, struct perf_sample_data data; int rctx; + preempt_disable_notrace(); rctx = perf_swevent_get_recursion_context(); if (rctx < 0) return; - data.addr = addr; - data.raw = NULL; + perf_sample_data_init(&data, addr); do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs); perf_swevent_put_recursion_context(rctx); + preempt_enable_notrace(); } static void perf_swevent_read(struct perf_event *event) @@ -3991,23 +4248,46 @@ static void perf_swevent_read(struct perf_event *event) static int perf_swevent_enable(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; + struct perf_cpu_context *cpuctx; + struct hlist_head *head; + + cpuctx = &__get_cpu_var(perf_cpu_context); if (hwc->sample_period) { hwc->last_period = hwc->sample_period; perf_swevent_set_period(event); } + + head = find_swevent_head(cpuctx, event); + if (WARN_ON_ONCE(!head)) + return -EINVAL; + + hlist_add_head_rcu(&event->hlist_entry, head); + return 0; } static void perf_swevent_disable(struct perf_event *event) { + hlist_del_rcu(&event->hlist_entry); +} + +static void perf_swevent_void(struct perf_event *event) +{ +} + +static int perf_swevent_int(struct perf_event *event) +{ + return 0; } static const struct pmu perf_ops_generic = { .enable = perf_swevent_enable, .disable = perf_swevent_disable, + .start = perf_swevent_int, + .stop = perf_swevent_void, .read = perf_swevent_read, - .unthrottle = perf_swevent_unthrottle, + .unthrottle = perf_swevent_void, /* hwc->interrupts already reset */ }; /* @@ -4022,22 +4302,14 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) struct perf_event *event; u64 period; - event = container_of(hrtimer, struct perf_event, hw.hrtimer); + event = container_of(hrtimer, struct perf_event, hw.hrtimer); event->pmu->read(event); - data.addr = 0; - data.raw = NULL; + perf_sample_data_init(&data, 0); data.period = event->hw.last_period; regs = get_irq_regs(); - /* - * In case we exclude kernel IPs or are somehow not in interrupt - * context, provide the next best thing, the user IP. - */ - if ((event->attr.exclude_kernel || !regs) && - !event->attr.exclude_user) - regs = task_pt_regs(current); - if (regs) { + if (regs && !perf_exclude_event(event, regs)) { if (!(event->attr.exclude_idle && current->pid == 0)) if (perf_event_overflow(event, 0, &data, regs)) ret = HRTIMER_NORESTART; @@ -4185,33 +4457,124 @@ static const struct pmu perf_ops_task_clock = { .read = task_clock_perf_event_read, }; -#ifdef CONFIG_EVENT_PROFILE +/* Deref the hlist from the update side */ +static inline struct swevent_hlist * +swevent_hlist_deref(struct perf_cpu_context *cpuctx) +{ + return rcu_dereference_protected(cpuctx->swevent_hlist, + lockdep_is_held(&cpuctx->hlist_mutex)); +} -void perf_tp_event(int event_id, u64 addr, u64 count, void *record, - int entry_size) +static void swevent_hlist_release_rcu(struct rcu_head *rcu_head) { - struct perf_raw_record raw = { - .size = entry_size, - .data = record, - }; + struct swevent_hlist *hlist; - struct perf_sample_data data = { - .addr = addr, - .raw = &raw, - }; + hlist = container_of(rcu_head, struct swevent_hlist, rcu_head); + kfree(hlist); +} - struct pt_regs *regs = get_irq_regs(); +static void swevent_hlist_release(struct perf_cpu_context *cpuctx) +{ + struct swevent_hlist *hlist = swevent_hlist_deref(cpuctx); - if (!regs) - regs = task_pt_regs(current); + if (!hlist) + return; - /* Trace events already protected against recursion */ - do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, - &data, regs); + rcu_assign_pointer(cpuctx->swevent_hlist, NULL); + call_rcu(&hlist->rcu_head, swevent_hlist_release_rcu); } -EXPORT_SYMBOL_GPL(perf_tp_event); -static int perf_tp_event_match(struct perf_event *event, +static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + + mutex_lock(&cpuctx->hlist_mutex); + + if (!--cpuctx->hlist_refcount) + swevent_hlist_release(cpuctx); + + mutex_unlock(&cpuctx->hlist_mutex); +} + +static void swevent_hlist_put(struct perf_event *event) +{ + int cpu; + + if (event->cpu != -1) { + swevent_hlist_put_cpu(event, event->cpu); + return; + } + + for_each_possible_cpu(cpu) + swevent_hlist_put_cpu(event, cpu); +} + +static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + int err = 0; + + mutex_lock(&cpuctx->hlist_mutex); + + if (!swevent_hlist_deref(cpuctx) && cpu_online(cpu)) { + struct swevent_hlist *hlist; + + hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); + if (!hlist) { + err = -ENOMEM; + goto exit; + } + rcu_assign_pointer(cpuctx->swevent_hlist, hlist); + } + cpuctx->hlist_refcount++; + exit: + mutex_unlock(&cpuctx->hlist_mutex); + + return err; +} + +static int swevent_hlist_get(struct perf_event *event) +{ + int err; + int cpu, failed_cpu; + + if (event->cpu != -1) + return swevent_hlist_get_cpu(event, event->cpu); + + get_online_cpus(); + for_each_possible_cpu(cpu) { + err = swevent_hlist_get_cpu(event, cpu); + if (err) { + failed_cpu = cpu; + goto fail; + } + } + put_online_cpus(); + + return 0; + fail: + for_each_possible_cpu(cpu) { + if (cpu == failed_cpu) + break; + swevent_hlist_put_cpu(event, cpu); + } + + put_online_cpus(); + return err; +} + +#ifdef CONFIG_EVENT_TRACING + +static const struct pmu perf_ops_tracepoint = { + .enable = perf_trace_enable, + .disable = perf_trace_disable, + .start = perf_swevent_int, + .stop = perf_swevent_void, + .read = perf_swevent_read, + .unthrottle = perf_swevent_void, +}; + +static int perf_tp_filter_match(struct perf_event *event, struct perf_sample_data *data) { void *record = data->raw->data; @@ -4221,13 +4584,55 @@ static int perf_tp_event_match(struct perf_event *event, return 0; } +static int perf_tp_event_match(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + /* + * All tracepoints are from kernel-space. + */ + if (event->attr.exclude_kernel) + return 0; + + if (!perf_tp_filter_match(event, data)) + return 0; + + return 1; +} + +void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, + struct pt_regs *regs, struct hlist_head *head) +{ + struct perf_sample_data data; + struct perf_event *event; + struct hlist_node *node; + + struct perf_raw_record raw = { + .size = entry_size, + .data = record, + }; + + perf_sample_data_init(&data, addr); + data.raw = &raw; + + rcu_read_lock(); + hlist_for_each_entry_rcu(event, node, head, hlist_entry) { + if (perf_tp_event_match(event, &data, regs)) + perf_swevent_add(event, count, 1, &data, regs); + } + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(perf_tp_event); + static void tp_perf_event_destroy(struct perf_event *event) { - ftrace_profile_disable(event->attr.config); + perf_trace_destroy(event); } static const struct pmu *tp_perf_event_init(struct perf_event *event) { + int err; + /* * Raw tracepoint data is a severe data leak, only allow root to * have these. @@ -4237,12 +4642,13 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event) !capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); - if (ftrace_profile_enable(event->attr.config)) + err = perf_trace_init(event); + if (err) return NULL; event->destroy = tp_perf_event_destroy; - return &perf_ops_generic; + return &perf_ops_tracepoint; } static int perf_event_set_filter(struct perf_event *event, void __user *arg) @@ -4270,12 +4676,6 @@ static void perf_event_free_filter(struct perf_event *event) #else -static int perf_tp_event_match(struct perf_event *event, - struct perf_sample_data *data) -{ - return 1; -} - static const struct pmu *tp_perf_event_init(struct perf_event *event) { return NULL; @@ -4290,7 +4690,7 @@ static void perf_event_free_filter(struct perf_event *event) { } -#endif /* CONFIG_EVENT_PROFILE */ +#endif /* CONFIG_EVENT_TRACING */ #ifdef CONFIG_HAVE_HW_BREAKPOINT static void bp_perf_event_destroy(struct perf_event *event) @@ -4316,8 +4716,7 @@ void perf_bp_event(struct perf_event *bp, void *data) struct perf_sample_data sample; struct pt_regs *regs = data; - sample.raw = NULL; - sample.addr = bp->attr.bp_addr; + perf_sample_data_init(&sample, bp->attr.bp_addr); if (!perf_exclude_event(bp, regs)) perf_swevent_add(bp, 1, 1, &sample, regs); @@ -4342,6 +4741,7 @@ static void sw_perf_event_destroy(struct perf_event *event) WARN_ON(event->parent); atomic_dec(&perf_swevent_enabled[event_id]); + swevent_hlist_put(event); } static const struct pmu *sw_perf_event_init(struct perf_event *event) @@ -4380,6 +4780,12 @@ static const struct pmu *sw_perf_event_init(struct perf_event *event) case PERF_COUNT_SW_ALIGNMENT_FAULTS: case PERF_COUNT_SW_EMULATION_FAULTS: if (!event->parent) { + int err; + + err = swevent_hlist_get(event); + if (err) + return ERR_PTR(err); + atomic_inc(&perf_swevent_enabled[event_id]); event->destroy = sw_perf_event_destroy; } @@ -4580,7 +4986,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, if (attr->type >= PERF_TYPE_MAX) return -EINVAL; - if (attr->__reserved_1 || attr->__reserved_2) + if (attr->__reserved_1) return -EINVAL; if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) @@ -4598,54 +5004,53 @@ err_size: goto out; } -static int perf_event_set_output(struct perf_event *event, int output_fd) +static int +perf_event_set_output(struct perf_event *event, struct perf_event *output_event) { - struct perf_event *output_event = NULL; - struct file *output_file = NULL; - struct perf_event *old_output; - int fput_needed = 0; + struct perf_mmap_data *data = NULL, *old_data = NULL; int ret = -EINVAL; - if (!output_fd) + if (!output_event) goto set; - output_file = fget_light(output_fd, &fput_needed); - if (!output_file) - return -EBADF; - - if (output_file->f_op != &perf_fops) + /* don't allow circular references */ + if (event == output_event) goto out; - output_event = output_file->private_data; - - /* Don't chain output fds */ - if (output_event->output) + /* + * Don't allow cross-cpu buffers + */ + if (output_event->cpu != event->cpu) goto out; - /* Don't set an output fd when we already have an output channel */ - if (event->data) + /* + * If its not a per-cpu buffer, it must be the same task. + */ + if (output_event->cpu == -1 && output_event->ctx != event->ctx) goto out; - atomic_long_inc(&output_file->f_count); - set: mutex_lock(&event->mmap_mutex); - old_output = event->output; - rcu_assign_pointer(event->output, output_event); - mutex_unlock(&event->mmap_mutex); + /* Can't redirect output if we've got an active mmap() */ + if (atomic_read(&event->mmap_count)) + goto unlock; - if (old_output) { - /* - * we need to make sure no existing perf_output_*() - * is still referencing this event. - */ - synchronize_rcu(); - fput(old_output->filp); + if (output_event) { + /* get the buffer we want to redirect to */ + data = perf_mmap_data_get(output_event); + if (!data) + goto unlock; } + old_data = event->data; + rcu_assign_pointer(event->data, data); ret = 0; +unlock: + mutex_unlock(&event->mmap_mutex); + + if (old_data) + perf_mmap_data_put(old_data); out: - fput_light(output_file, fput_needed); return ret; } @@ -4661,13 +5066,13 @@ SYSCALL_DEFINE5(perf_event_open, struct perf_event_attr __user *, attr_uptr, pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) { - struct perf_event *event, *group_leader; + struct perf_event *event, *group_leader = NULL, *output_event = NULL; struct perf_event_attr attr; struct perf_event_context *ctx; struct file *event_file = NULL; struct file *group_file = NULL; + int event_fd; int fput_needed = 0; - int fput_needed2 = 0; int err; /* for future expandability... */ @@ -4688,26 +5093,38 @@ SYSCALL_DEFINE5(perf_event_open, return -EINVAL; } + event_fd = get_unused_fd_flags(O_RDWR); + if (event_fd < 0) + return event_fd; + /* * Get the target context (task or percpu): */ ctx = find_get_context(pid, cpu); - if (IS_ERR(ctx)) - return PTR_ERR(ctx); + if (IS_ERR(ctx)) { + err = PTR_ERR(ctx); + goto err_fd; + } + + if (group_fd != -1) { + group_leader = perf_fget_light(group_fd, &fput_needed); + if (IS_ERR(group_leader)) { + err = PTR_ERR(group_leader); + goto err_put_context; + } + group_file = group_leader->filp; + if (flags & PERF_FLAG_FD_OUTPUT) + output_event = group_leader; + if (flags & PERF_FLAG_FD_NO_GROUP) + group_leader = NULL; + } /* * Look up the group leader (we will attach this event to it): */ - group_leader = NULL; - if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { + if (group_leader) { err = -EINVAL; - group_file = fget_light(group_fd, &fput_needed); - if (!group_file) - goto err_put_context; - if (group_file->f_op != &perf_fops) - goto err_put_context; - group_leader = group_file->private_data; /* * Do not allow a recursive hierarchy (this new sibling * becoming part of another group-sibling): @@ -4729,22 +5146,21 @@ SYSCALL_DEFINE5(perf_event_open, event = perf_event_alloc(&attr, cpu, ctx, group_leader, NULL, NULL, GFP_KERNEL); - err = PTR_ERR(event); - if (IS_ERR(event)) + if (IS_ERR(event)) { + err = PTR_ERR(event); goto err_put_context; + } - err = anon_inode_getfd("[perf_event]", &perf_fops, event, O_RDWR); - if (err < 0) - goto err_free_put_context; + if (output_event) { + err = perf_event_set_output(event, output_event); + if (err) + goto err_free_put_context; + } - event_file = fget_light(err, &fput_needed2); - if (!event_file) + event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, O_RDWR); + if (IS_ERR(event_file)) { + err = PTR_ERR(event_file); goto err_free_put_context; - - if (flags & PERF_FLAG_FD_OUTPUT) { - err = perf_event_set_output(event, group_fd); - if (err) - goto err_fput_free_put_context; } event->filp = event_file; @@ -4760,19 +5176,23 @@ SYSCALL_DEFINE5(perf_event_open, list_add_tail(&event->owner_entry, ¤t->perf_event_list); mutex_unlock(¤t->perf_event_mutex); -err_fput_free_put_context: - fput_light(event_file, fput_needed2); + /* + * Drop the reference on the group_event after placing the + * new event on the sibling_list. This ensures destruction + * of the group leader will find the pointer to itself in + * perf_group_detach(). + */ + fput_light(group_file, fput_needed); + fd_install(event_fd, event_file); + return event_fd; err_free_put_context: - if (err < 0) - kfree(event); - + free_event(event); err_put_context: - if (err < 0) - put_ctx(ctx); - fput_light(group_file, fput_needed); - + put_ctx(ctx); +err_fd: + put_unused_fd(event_fd); return err; } @@ -4871,8 +5291,15 @@ inherit_event(struct perf_event *parent_event, else child_event->state = PERF_EVENT_STATE_OFF; - if (parent_event->attr.freq) - child_event->hw.sample_period = parent_event->hw.sample_period; + if (parent_event->attr.freq) { + u64 sample_period = parent_event->hw.sample_period; + struct hw_perf_event *hwc = &child_event->hw; + + hwc->sample_period = sample_period; + hwc->last_period = sample_period; + + atomic64_set(&hwc->period_left, sample_period); + } child_event->overflow_handler = parent_event->overflow_handler; @@ -5037,10 +5464,14 @@ void perf_event_exit_task(struct task_struct *child) * * But since its the parent context it won't be the same instance. */ - mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); + mutex_lock(&child_ctx->mutex); again: - list_for_each_entry_safe(child_event, tmp, &child_ctx->group_list, + list_for_each_entry_safe(child_event, tmp, &child_ctx->pinned_groups, + group_entry) + __perf_event_exit_task(child_event, child_ctx, child); + + list_for_each_entry_safe(child_event, tmp, &child_ctx->flexible_groups, group_entry) __perf_event_exit_task(child_event, child_ctx, child); @@ -5049,7 +5480,8 @@ again: * its siblings to the list, but we obtained 'tmp' before that which * will still point to the list head terminating the iteration. */ - if (!list_empty(&child_ctx->group_list)) + if (!list_empty(&child_ctx->pinned_groups) || + !list_empty(&child_ctx->flexible_groups)) goto again; mutex_unlock(&child_ctx->mutex); @@ -5057,6 +5489,25 @@ again: put_ctx(child_ctx); } +static void perf_free_event(struct perf_event *event, + struct perf_event_context *ctx) +{ + struct perf_event *parent = event->parent; + + if (WARN_ON_ONCE(!parent)) + return; + + mutex_lock(&parent->child_mutex); + list_del_init(&event->child_list); + mutex_unlock(&parent->child_mutex); + + fput(parent->filp); + + perf_group_detach(event); + list_del_event(event, ctx); + free_event(event); +} + /* * free an unexposed, unused context as created by inheritance by * init_task below, used by fork() in case of fail. @@ -5071,36 +5522,70 @@ void perf_event_free_task(struct task_struct *task) mutex_lock(&ctx->mutex); again: - list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) { - struct perf_event *parent = event->parent; + list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, group_entry) + perf_free_event(event, ctx); - if (WARN_ON_ONCE(!parent)) - continue; + list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, + group_entry) + perf_free_event(event, ctx); - mutex_lock(&parent->child_mutex); - list_del_init(&event->child_list); - mutex_unlock(&parent->child_mutex); + if (!list_empty(&ctx->pinned_groups) || + !list_empty(&ctx->flexible_groups)) + goto again; - fput(parent->filp); + mutex_unlock(&ctx->mutex); - list_del_event(event, ctx); - free_event(event); + put_ctx(ctx); +} + +static int +inherit_task_group(struct perf_event *event, struct task_struct *parent, + struct perf_event_context *parent_ctx, + struct task_struct *child, + int *inherited_all) +{ + int ret; + struct perf_event_context *child_ctx = child->perf_event_ctxp; + + if (!event->attr.inherit) { + *inherited_all = 0; + return 0; } - if (!list_empty(&ctx->group_list)) - goto again; + if (!child_ctx) { + /* + * This is executed from the parent task context, so + * inherit events that have been marked for cloning. + * First allocate and initialize a context for the + * child. + */ - mutex_unlock(&ctx->mutex); + child_ctx = kzalloc(sizeof(struct perf_event_context), + GFP_KERNEL); + if (!child_ctx) + return -ENOMEM; - put_ctx(ctx); + __perf_event_init_context(child_ctx, child); + child->perf_event_ctxp = child_ctx; + get_task_struct(child); + } + + ret = inherit_group(event, parent, parent_ctx, + child, child_ctx); + + if (ret) + *inherited_all = 0; + + return ret; } + /* * Initialize the perf_event context in task_struct */ int perf_event_init_task(struct task_struct *child) { - struct perf_event_context *child_ctx = NULL, *parent_ctx; + struct perf_event_context *child_ctx, *parent_ctx; struct perf_event_context *cloned_ctx; struct perf_event *event; struct task_struct *parent = current; @@ -5138,41 +5623,22 @@ int perf_event_init_task(struct task_struct *child) * We dont have to disable NMIs - we are only looking at * the list, not manipulating it: */ - list_for_each_entry(event, &parent_ctx->group_list, group_entry) { - - if (!event->attr.inherit) { - inherited_all = 0; - continue; - } - - if (!child->perf_event_ctxp) { - /* - * This is executed from the parent task context, so - * inherit events that have been marked for cloning. - * First allocate and initialize a context for the - * child. - */ - - child_ctx = kzalloc(sizeof(struct perf_event_context), - GFP_KERNEL); - if (!child_ctx) { - ret = -ENOMEM; - break; - } - - __perf_event_init_context(child_ctx, child); - child->perf_event_ctxp = child_ctx; - get_task_struct(child); - } + list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { + ret = inherit_task_group(event, parent, parent_ctx, child, + &inherited_all); + if (ret) + break; + } - ret = inherit_group(event, parent, parent_ctx, - child, child_ctx); - if (ret) { - inherited_all = 0; + list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { + ret = inherit_task_group(event, parent, parent_ctx, child, + &inherited_all); + if (ret) break; - } } + child_ctx = child->perf_event_ctxp; + if (child_ctx && inherited_all) { /* * Mark the child context as a clone of the parent @@ -5200,18 +5666,37 @@ int perf_event_init_task(struct task_struct *child) return ret; } +static void __init perf_event_init_all_cpus(void) +{ + int cpu; + struct perf_cpu_context *cpuctx; + + for_each_possible_cpu(cpu) { + cpuctx = &per_cpu(perf_cpu_context, cpu); + mutex_init(&cpuctx->hlist_mutex); + __perf_event_init_context(&cpuctx->ctx, NULL); + } +} + static void __cpuinit perf_event_init_cpu(int cpu) { struct perf_cpu_context *cpuctx; cpuctx = &per_cpu(perf_cpu_context, cpu); - __perf_event_init_context(&cpuctx->ctx, NULL); spin_lock(&perf_resource_lock); cpuctx->max_pertask = perf_max_events - perf_reserved_percpu; spin_unlock(&perf_resource_lock); - hw_perf_event_setup(cpu); + mutex_lock(&cpuctx->hlist_mutex); + if (cpuctx->hlist_refcount > 0) { + struct swevent_hlist *hlist; + + hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); + WARN_ON_ONCE(!hlist); + rcu_assign_pointer(cpuctx->swevent_hlist, hlist); + } + mutex_unlock(&cpuctx->hlist_mutex); } #ifdef CONFIG_HOTPLUG_CPU @@ -5221,7 +5706,9 @@ static void __perf_event_exit_cpu(void *info) struct perf_event_context *ctx = &cpuctx->ctx; struct perf_event *event, *tmp; - list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) + list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, group_entry) + __perf_event_remove_from_context(event); + list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, group_entry) __perf_event_remove_from_context(event); } static void perf_event_exit_cpu(int cpu) @@ -5229,6 +5716,10 @@ static void perf_event_exit_cpu(int cpu) struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); struct perf_event_context *ctx = &cpuctx->ctx; + mutex_lock(&cpuctx->hlist_mutex); + swevent_hlist_release(cpuctx); + mutex_unlock(&cpuctx->hlist_mutex); + mutex_lock(&ctx->mutex); smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1); mutex_unlock(&ctx->mutex); @@ -5249,11 +5740,6 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) perf_event_init_cpu(cpu); break; - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hw_perf_event_setup_online(cpu); - break; - case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: perf_event_exit_cpu(cpu); @@ -5276,6 +5762,7 @@ static struct notifier_block __cpuinitdata perf_cpu_nb = { void __init perf_event_init(void) { + perf_event_init_all_cpus(); perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, @@ -5283,13 +5770,16 @@ void __init perf_event_init(void) register_cpu_notifier(&perf_cpu_nb); } -static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) +static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, + struct sysdev_class_attribute *attr, + char *buf) { return sprintf(buf, "%d\n", perf_reserved_percpu); } static ssize_t perf_set_reserve_percpu(struct sysdev_class *class, + struct sysdev_class_attribute *attr, const char *buf, size_t count) { @@ -5318,13 +5808,17 @@ perf_set_reserve_percpu(struct sysdev_class *class, return count; } -static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) +static ssize_t perf_show_overcommit(struct sysdev_class *class, + struct sysdev_class_attribute *attr, + char *buf) { return sprintf(buf, "%d\n", perf_overcommit); } static ssize_t -perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) +perf_set_overcommit(struct sysdev_class *class, + struct sysdev_class_attribute *attr, + const char *buf, size_t count) { unsigned long val; int err; |