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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 11:02:58 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 11:02:58 -0500
commit35b740e4662ef386f0c60e1b60aaf5b44db9914c (patch)
tree502a8f9499bc1b4cb3300d666dab2d01a1921224 /kernel/events/core.c
parent423d091dfe58d3109d84c408810a7cfa82f6f184 (diff)
parent9e183426bfb52bb44bf3c443d6587e4d02478603 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (106 commits) perf kvm: Fix copy & paste error in description perf script: Kill script_spec__delete perf top: Fix a memory leak perf stat: Introduce get_ratio_color() helper perf session: Remove impossible condition check perf tools: Fix feature-bits rework fallout, remove unused variable perf script: Add generic perl handler to process events perf tools: Use for_each_set_bit() to iterate over feature flags perf tools: Unify handling of features when writing feature section perf report: Accept fifos as input file perf tools: Moving code in some files perf tools: Fix out-of-bound access to struct perf_session perf tools: Continue processing header on unknown features perf tools: Improve macros for struct feature_ops perf: builtin-record: Document and check that mmap_pages must be a power of two. perf: builtin-record: Provide advice if mmap'ing fails with EPERM. perf tools: Fix truncated annotation perf script: look up thread using tid instead of pid perf tools: Look up thread names for system wide profiling perf tools: Fix comm for processes with named threads ...
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r--kernel/events/core.c296
1 files changed, 53 insertions, 243 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index fc0e7ff11dda..890eb02c2f21 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -128,7 +128,7 @@ enum event_type_t {
128 * perf_sched_events : >0 events exist 128 * perf_sched_events : >0 events exist
129 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu 129 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
130 */ 130 */
131struct jump_label_key perf_sched_events __read_mostly; 131struct jump_label_key_deferred perf_sched_events __read_mostly;
132static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); 132static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
133 133
134static atomic_t nr_mmap_events __read_mostly; 134static atomic_t nr_mmap_events __read_mostly;
@@ -1130,6 +1130,8 @@ event_sched_out(struct perf_event *event,
1130 if (!is_software_event(event)) 1130 if (!is_software_event(event))
1131 cpuctx->active_oncpu--; 1131 cpuctx->active_oncpu--;
1132 ctx->nr_active--; 1132 ctx->nr_active--;
1133 if (event->attr.freq && event->attr.sample_freq)
1134 ctx->nr_freq--;
1133 if (event->attr.exclusive || !cpuctx->active_oncpu) 1135 if (event->attr.exclusive || !cpuctx->active_oncpu)
1134 cpuctx->exclusive = 0; 1136 cpuctx->exclusive = 0;
1135} 1137}
@@ -1325,6 +1327,7 @@ retry:
1325 } 1327 }
1326 raw_spin_unlock_irq(&ctx->lock); 1328 raw_spin_unlock_irq(&ctx->lock);
1327} 1329}
1330EXPORT_SYMBOL_GPL(perf_event_disable);
1328 1331
1329static void perf_set_shadow_time(struct perf_event *event, 1332static void perf_set_shadow_time(struct perf_event *event,
1330 struct perf_event_context *ctx, 1333 struct perf_event_context *ctx,
@@ -1406,6 +1409,8 @@ event_sched_in(struct perf_event *event,
1406 if (!is_software_event(event)) 1409 if (!is_software_event(event))
1407 cpuctx->active_oncpu++; 1410 cpuctx->active_oncpu++;
1408 ctx->nr_active++; 1411 ctx->nr_active++;
1412 if (event->attr.freq && event->attr.sample_freq)
1413 ctx->nr_freq++;
1409 1414
1410 if (event->attr.exclusive) 1415 if (event->attr.exclusive)
1411 cpuctx->exclusive = 1; 1416 cpuctx->exclusive = 1;
@@ -1662,8 +1667,7 @@ retry:
1662 * Note: this works for group members as well as group leaders 1667 * Note: this works for group members as well as group leaders
1663 * since the non-leader members' sibling_lists will be empty. 1668 * since the non-leader members' sibling_lists will be empty.
1664 */ 1669 */
1665static void __perf_event_mark_enabled(struct perf_event *event, 1670static void __perf_event_mark_enabled(struct perf_event *event)
1666 struct perf_event_context *ctx)
1667{ 1671{
1668 struct perf_event *sub; 1672 struct perf_event *sub;
1669 u64 tstamp = perf_event_time(event); 1673 u64 tstamp = perf_event_time(event);
@@ -1701,7 +1705,7 @@ static int __perf_event_enable(void *info)
1701 */ 1705 */
1702 perf_cgroup_set_timestamp(current, ctx); 1706 perf_cgroup_set_timestamp(current, ctx);
1703 1707
1704 __perf_event_mark_enabled(event, ctx); 1708 __perf_event_mark_enabled(event);
1705 1709
1706 if (!event_filter_match(event)) { 1710 if (!event_filter_match(event)) {
1707 if (is_cgroup_event(event)) 1711 if (is_cgroup_event(event))
@@ -1782,7 +1786,7 @@ void perf_event_enable(struct perf_event *event)
1782 1786
1783retry: 1787retry:
1784 if (!ctx->is_active) { 1788 if (!ctx->is_active) {
1785 __perf_event_mark_enabled(event, ctx); 1789 __perf_event_mark_enabled(event);
1786 goto out; 1790 goto out;
1787 } 1791 }
1788 1792
@@ -1809,6 +1813,7 @@ retry:
1809out: 1813out:
1810 raw_spin_unlock_irq(&ctx->lock); 1814 raw_spin_unlock_irq(&ctx->lock);
1811} 1815}
1816EXPORT_SYMBOL_GPL(perf_event_enable);
1812 1817
1813int perf_event_refresh(struct perf_event *event, int refresh) 1818int perf_event_refresh(struct perf_event *event, int refresh)
1814{ 1819{
@@ -2327,6 +2332,9 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period)
2327 u64 interrupts, now; 2332 u64 interrupts, now;
2328 s64 delta; 2333 s64 delta;
2329 2334
2335 if (!ctx->nr_freq)
2336 return;
2337
2330 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { 2338 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
2331 if (event->state != PERF_EVENT_STATE_ACTIVE) 2339 if (event->state != PERF_EVENT_STATE_ACTIVE)
2332 continue; 2340 continue;
@@ -2382,12 +2390,14 @@ static void perf_rotate_context(struct perf_cpu_context *cpuctx)
2382{ 2390{
2383 u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC; 2391 u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC;
2384 struct perf_event_context *ctx = NULL; 2392 struct perf_event_context *ctx = NULL;
2385 int rotate = 0, remove = 1; 2393 int rotate = 0, remove = 1, freq = 0;
2386 2394
2387 if (cpuctx->ctx.nr_events) { 2395 if (cpuctx->ctx.nr_events) {
2388 remove = 0; 2396 remove = 0;
2389 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) 2397 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
2390 rotate = 1; 2398 rotate = 1;
2399 if (cpuctx->ctx.nr_freq)
2400 freq = 1;
2391 } 2401 }
2392 2402
2393 ctx = cpuctx->task_ctx; 2403 ctx = cpuctx->task_ctx;
@@ -2395,33 +2405,40 @@ static void perf_rotate_context(struct perf_cpu_context *cpuctx)
2395 remove = 0; 2405 remove = 0;
2396 if (ctx->nr_events != ctx->nr_active) 2406 if (ctx->nr_events != ctx->nr_active)
2397 rotate = 1; 2407 rotate = 1;
2408 if (ctx->nr_freq)
2409 freq = 1;
2398 } 2410 }
2399 2411
2412 if (!rotate && !freq)
2413 goto done;
2414
2400 perf_ctx_lock(cpuctx, cpuctx->task_ctx); 2415 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
2401 perf_pmu_disable(cpuctx->ctx.pmu); 2416 perf_pmu_disable(cpuctx->ctx.pmu);
2402 perf_ctx_adjust_freq(&cpuctx->ctx, interval);
2403 if (ctx)
2404 perf_ctx_adjust_freq(ctx, interval);
2405 2417
2406 if (!rotate) 2418 if (freq) {
2407 goto done; 2419 perf_ctx_adjust_freq(&cpuctx->ctx, interval);
2420 if (ctx)
2421 perf_ctx_adjust_freq(ctx, interval);
2422 }
2408 2423
2409 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); 2424 if (rotate) {
2410 if (ctx) 2425 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
2411 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE); 2426 if (ctx)
2427 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
2412 2428
2413 rotate_ctx(&cpuctx->ctx); 2429 rotate_ctx(&cpuctx->ctx);
2414 if (ctx) 2430 if (ctx)
2415 rotate_ctx(ctx); 2431 rotate_ctx(ctx);
2416 2432
2417 perf_event_sched_in(cpuctx, ctx, current); 2433 perf_event_sched_in(cpuctx, ctx, current);
2434 }
2435
2436 perf_pmu_enable(cpuctx->ctx.pmu);
2437 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2418 2438
2419done: 2439done:
2420 if (remove) 2440 if (remove)
2421 list_del_init(&cpuctx->rotation_list); 2441 list_del_init(&cpuctx->rotation_list);
2422
2423 perf_pmu_enable(cpuctx->ctx.pmu);
2424 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2425} 2442}
2426 2443
2427void perf_event_task_tick(void) 2444void perf_event_task_tick(void)
@@ -2448,7 +2465,7 @@ static int event_enable_on_exec(struct perf_event *event,
2448 if (event->state >= PERF_EVENT_STATE_INACTIVE) 2465 if (event->state >= PERF_EVENT_STATE_INACTIVE)
2449 return 0; 2466 return 0;
2450 2467
2451 __perf_event_mark_enabled(event, ctx); 2468 __perf_event_mark_enabled(event);
2452 2469
2453 return 1; 2470 return 1;
2454} 2471}
@@ -2480,13 +2497,7 @@ static void perf_event_enable_on_exec(struct perf_event_context *ctx)
2480 raw_spin_lock(&ctx->lock); 2497 raw_spin_lock(&ctx->lock);
2481 task_ctx_sched_out(ctx); 2498 task_ctx_sched_out(ctx);
2482 2499
2483 list_for_each_entry(event, &ctx->pinned_groups, group_entry) { 2500 list_for_each_entry(event, &ctx->event_list, event_entry) {
2484 ret = event_enable_on_exec(event, ctx);
2485 if (ret)
2486 enabled = 1;
2487 }
2488
2489 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
2490 ret = event_enable_on_exec(event, ctx); 2501 ret = event_enable_on_exec(event, ctx);
2491 if (ret) 2502 if (ret)
2492 enabled = 1; 2503 enabled = 1;
@@ -2574,215 +2585,6 @@ static u64 perf_event_read(struct perf_event *event)
2574} 2585}
2575 2586
2576/* 2587/*
2577 * Callchain support
2578 */
2579
2580struct callchain_cpus_entries {
2581 struct rcu_head rcu_head;
2582 struct perf_callchain_entry *cpu_entries[0];
2583};
2584
2585static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]);
2586static atomic_t nr_callchain_events;
2587static DEFINE_MUTEX(callchain_mutex);
2588struct callchain_cpus_entries *callchain_cpus_entries;
2589
2590
2591__weak void perf_callchain_kernel(struct perf_callchain_entry *entry,
2592 struct pt_regs *regs)
2593{
2594}
2595
2596__weak void perf_callchain_user(struct perf_callchain_entry *entry,
2597 struct pt_regs *regs)
2598{
2599}
2600
2601static void release_callchain_buffers_rcu(struct rcu_head *head)
2602{
2603 struct callchain_cpus_entries *entries;
2604 int cpu;
2605
2606 entries = container_of(head, struct callchain_cpus_entries, rcu_head);
2607
2608 for_each_possible_cpu(cpu)
2609 kfree(entries->cpu_entries[cpu]);
2610
2611 kfree(entries);
2612}
2613
2614static void release_callchain_buffers(void)
2615{
2616 struct callchain_cpus_entries *entries;
2617
2618 entries = callchain_cpus_entries;
2619 rcu_assign_pointer(callchain_cpus_entries, NULL);
2620 call_rcu(&entries->rcu_head, release_callchain_buffers_rcu);
2621}
2622
2623static int alloc_callchain_buffers(void)
2624{
2625 int cpu;
2626 int size;
2627 struct callchain_cpus_entries *entries;
2628
2629 /*
2630 * We can't use the percpu allocation API for data that can be
2631 * accessed from NMI. Use a temporary manual per cpu allocation
2632 * until that gets sorted out.
2633 */
2634 size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
2635
2636 entries = kzalloc(size, GFP_KERNEL);
2637 if (!entries)
2638 return -ENOMEM;
2639
2640 size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS;
2641
2642 for_each_possible_cpu(cpu) {
2643 entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL,
2644 cpu_to_node(cpu));
2645 if (!entries->cpu_entries[cpu])
2646 goto fail;
2647 }
2648
2649 rcu_assign_pointer(callchain_cpus_entries, entries);
2650
2651 return 0;
2652
2653fail:
2654 for_each_possible_cpu(cpu)
2655 kfree(entries->cpu_entries[cpu]);
2656 kfree(entries);
2657
2658 return -ENOMEM;
2659}
2660
2661static int get_callchain_buffers(void)
2662{
2663 int err = 0;
2664 int count;
2665
2666 mutex_lock(&callchain_mutex);
2667
2668 count = atomic_inc_return(&nr_callchain_events);
2669 if (WARN_ON_ONCE(count < 1)) {
2670 err = -EINVAL;
2671 goto exit;
2672 }
2673
2674 if (count > 1) {
2675 /* If the allocation failed, give up */
2676 if (!callchain_cpus_entries)
2677 err = -ENOMEM;
2678 goto exit;
2679 }
2680
2681 err = alloc_callchain_buffers();
2682 if (err)
2683 release_callchain_buffers();
2684exit:
2685 mutex_unlock(&callchain_mutex);
2686
2687 return err;
2688}
2689
2690static void put_callchain_buffers(void)
2691{
2692 if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) {
2693 release_callchain_buffers();
2694 mutex_unlock(&callchain_mutex);
2695 }
2696}
2697
2698static int get_recursion_context(int *recursion)
2699{
2700 int rctx;
2701
2702 if (in_nmi())
2703 rctx = 3;
2704 else if (in_irq())
2705 rctx = 2;
2706 else if (in_softirq())
2707 rctx = 1;
2708 else
2709 rctx = 0;
2710
2711 if (recursion[rctx])
2712 return -1;
2713
2714 recursion[rctx]++;
2715 barrier();
2716
2717 return rctx;
2718}
2719
2720static inline void put_recursion_context(int *recursion, int rctx)
2721{
2722 barrier();
2723 recursion[rctx]--;
2724}
2725
2726static struct perf_callchain_entry *get_callchain_entry(int *rctx)
2727{
2728 int cpu;
2729 struct callchain_cpus_entries *entries;
2730
2731 *rctx = get_recursion_context(__get_cpu_var(callchain_recursion));
2732 if (*rctx == -1)
2733 return NULL;
2734
2735 entries = rcu_dereference(callchain_cpus_entries);
2736 if (!entries)
2737 return NULL;
2738
2739 cpu = smp_processor_id();
2740
2741 return &entries->cpu_entries[cpu][*rctx];
2742}
2743
2744static void
2745put_callchain_entry(int rctx)
2746{
2747 put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
2748}
2749
2750static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
2751{
2752 int rctx;
2753 struct perf_callchain_entry *entry;
2754
2755
2756 entry = get_callchain_entry(&rctx);
2757 if (rctx == -1)
2758 return NULL;
2759
2760 if (!entry)
2761 goto exit_put;
2762
2763 entry->nr = 0;
2764
2765 if (!user_mode(regs)) {
2766 perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
2767 perf_callchain_kernel(entry, regs);
2768 if (current->mm)
2769 regs = task_pt_regs(current);
2770 else
2771 regs = NULL;
2772 }
2773
2774 if (regs) {
2775 perf_callchain_store(entry, PERF_CONTEXT_USER);
2776 perf_callchain_user(entry, regs);
2777 }
2778
2779exit_put:
2780 put_callchain_entry(rctx);
2781
2782 return entry;
2783}
2784
2785/*
2786 * Initialize the perf_event context in a task_struct: 2588 * Initialize the perf_event context in a task_struct:
2787 */ 2589 */
2788static void __perf_event_init_context(struct perf_event_context *ctx) 2590static void __perf_event_init_context(struct perf_event_context *ctx)
@@ -2946,7 +2748,7 @@ static void free_event(struct perf_event *event)
2946 2748
2947 if (!event->parent) { 2749 if (!event->parent) {
2948 if (event->attach_state & PERF_ATTACH_TASK) 2750 if (event->attach_state & PERF_ATTACH_TASK)
2949 jump_label_dec(&perf_sched_events); 2751 jump_label_dec_deferred(&perf_sched_events);
2950 if (event->attr.mmap || event->attr.mmap_data) 2752 if (event->attr.mmap || event->attr.mmap_data)
2951 atomic_dec(&nr_mmap_events); 2753 atomic_dec(&nr_mmap_events);
2952 if (event->attr.comm) 2754 if (event->attr.comm)
@@ -2957,7 +2759,7 @@ static void free_event(struct perf_event *event)
2957 put_callchain_buffers(); 2759 put_callchain_buffers();
2958 if (is_cgroup_event(event)) { 2760 if (is_cgroup_event(event)) {
2959 atomic_dec(&per_cpu(perf_cgroup_events, event->cpu)); 2761 atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
2960 jump_label_dec(&perf_sched_events); 2762 jump_label_dec_deferred(&perf_sched_events);
2961 } 2763 }
2962 } 2764 }
2963 2765
@@ -4820,7 +4622,6 @@ static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
4820 struct hw_perf_event *hwc = &event->hw; 4622 struct hw_perf_event *hwc = &event->hw;
4821 int throttle = 0; 4623 int throttle = 0;
4822 4624
4823 data->period = event->hw.last_period;
4824 if (!overflow) 4625 if (!overflow)
4825 overflow = perf_swevent_set_period(event); 4626 overflow = perf_swevent_set_period(event);
4826 4627
@@ -4854,6 +4655,12 @@ static void perf_swevent_event(struct perf_event *event, u64 nr,
4854 if (!is_sampling_event(event)) 4655 if (!is_sampling_event(event))
4855 return; 4656 return;
4856 4657
4658 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
4659 data->period = nr;
4660 return perf_swevent_overflow(event, 1, data, regs);
4661 } else
4662 data->period = event->hw.last_period;
4663
4857 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) 4664 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
4858 return perf_swevent_overflow(event, 1, data, regs); 4665 return perf_swevent_overflow(event, 1, data, regs);
4859 4666
@@ -5981,7 +5788,7 @@ done:
5981 5788
5982 if (!event->parent) { 5789 if (!event->parent) {
5983 if (event->attach_state & PERF_ATTACH_TASK) 5790 if (event->attach_state & PERF_ATTACH_TASK)
5984 jump_label_inc(&perf_sched_events); 5791 jump_label_inc(&perf_sched_events.key);
5985 if (event->attr.mmap || event->attr.mmap_data) 5792 if (event->attr.mmap || event->attr.mmap_data)
5986 atomic_inc(&nr_mmap_events); 5793 atomic_inc(&nr_mmap_events);
5987 if (event->attr.comm) 5794 if (event->attr.comm)
@@ -6219,7 +6026,7 @@ SYSCALL_DEFINE5(perf_event_open,
6219 * - that may need work on context switch 6026 * - that may need work on context switch
6220 */ 6027 */
6221 atomic_inc(&per_cpu(perf_cgroup_events, event->cpu)); 6028 atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
6222 jump_label_inc(&perf_sched_events); 6029 jump_label_inc(&perf_sched_events.key);
6223 } 6030 }
6224 6031
6225 /* 6032 /*
@@ -7065,6 +6872,9 @@ void __init perf_event_init(void)
7065 6872
7066 ret = init_hw_breakpoint(); 6873 ret = init_hw_breakpoint();
7067 WARN(ret, "hw_breakpoint initialization failed with: %d", ret); 6874 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
6875
6876 /* do not patch jump label more than once per second */
6877 jump_label_rate_limit(&perf_sched_events, HZ);
7068} 6878}
7069 6879
7070static int __init perf_event_sysfs_init(void) 6880static int __init perf_event_sysfs_init(void)