diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 1 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 2 | ||||
| -rw-r--r-- | kernel/events/core.c | 174 | ||||
| -rw-r--r-- | tools/Makefile | 6 | ||||
| -rw-r--r-- | tools/lib/lockdep/Makefile | 5 |
5 files changed, 102 insertions, 86 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index aa333d96688..adb02aa62af 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -169,7 +169,6 @@ static struct event_constraint intel_slm_event_constraints[] __read_mostly = { FIXED_EVENT_CONSTRAINT(0x00c0, 0), /* INST_RETIRED.ANY */ FIXED_EVENT_CONSTRAINT(0x003c, 1), /* CPU_CLK_UNHALTED.CORE */ - FIXED_EVENT_CONSTRAINT(0x013c, 2), /* CPU_CLK_UNHALTED.REF */ FIXED_EVENT_CONSTRAINT(0x0300, 2), /* pseudo CPU_CLK_UNHALTED.REF */ EVENT_CONSTRAINT_END }; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 3356abcfff1..3ef6ea12806 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -402,6 +402,8 @@ struct perf_event { struct ring_buffer *rb; struct list_head rb_entry; + unsigned long rcu_batches; + int rcu_pending; /* poll related */ wait_queue_head_t waitq; diff --git a/kernel/events/core.c b/kernel/events/core.c index f83a71a3e46..440eefc6739 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1443,6 +1443,11 @@ group_sched_out(struct perf_event *group_event, cpuctx->exclusive = 0; } +struct remove_event { + struct perf_event *event; + bool detach_group; +}; + /* * Cross CPU call to remove a performance event * @@ -1451,12 +1456,15 @@ group_sched_out(struct perf_event *group_event, */ static int __perf_remove_from_context(void *info) { - struct perf_event *event = info; + struct remove_event *re = info; + struct perf_event *event = re->event; struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = __get_cpu_context(ctx); raw_spin_lock(&ctx->lock); event_sched_out(event, cpuctx, ctx); + if (re->detach_group) + perf_group_detach(event); list_del_event(event, ctx); if (!ctx->nr_events && cpuctx->task_ctx == ctx) { ctx->is_active = 0; @@ -1481,10 +1489,14 @@ static int __perf_remove_from_context(void *info) * When called from perf_event_exit_task, it's OK because the * context has been detached from its task. */ -static void perf_remove_from_context(struct perf_event *event) +static void perf_remove_from_context(struct perf_event *event, bool detach_group) { struct perf_event_context *ctx = event->ctx; struct task_struct *task = ctx->task; + struct remove_event re = { + .event = event, + .detach_group = detach_group, + }; lockdep_assert_held(&ctx->mutex); @@ -1493,12 +1505,12 @@ static void perf_remove_from_context(struct perf_event *event) * Per cpu events are removed via an smp call and * the removal is always successful. */ - cpu_function_call(event->cpu, __perf_remove_from_context, event); + cpu_function_call(event->cpu, __perf_remove_from_context, &re); return; } retry: - if (!task_function_call(task, __perf_remove_from_context, event)) + if (!task_function_call(task, __perf_remove_from_context, &re)) return; raw_spin_lock_irq(&ctx->lock); @@ -1515,6 +1527,8 @@ retry: * Since the task isn't running, its safe to remove the event, us * holding the ctx->lock ensures the task won't get scheduled in. */ + if (detach_group) + perf_group_detach(event); list_del_event(event, ctx); raw_spin_unlock_irq(&ctx->lock); } @@ -3178,7 +3192,8 @@ static void free_event_rcu(struct rcu_head *head) } static void ring_buffer_put(struct ring_buffer *rb); -static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb); +static void ring_buffer_attach(struct perf_event *event, + struct ring_buffer *rb); static void unaccount_event_cpu(struct perf_event *event, int cpu) { @@ -3238,8 +3253,6 @@ static void free_event(struct perf_event *event) unaccount_event(event); if (event->rb) { - struct ring_buffer *rb; - /* * Can happen when we close an event with re-directed output. * @@ -3247,12 +3260,7 @@ static void free_event(struct perf_event *event) * over us; possibly making our ring_buffer_put() the last. */ mutex_lock(&event->mmap_mutex); - rb = event->rb; - if (rb) { - rcu_assign_pointer(event->rb, NULL); - ring_buffer_detach(event, rb); - ring_buffer_put(rb); /* could be last */ - } + ring_buffer_attach(event, NULL); mutex_unlock(&event->mmap_mutex); } @@ -3281,10 +3289,7 @@ int perf_event_release_kernel(struct perf_event *event) * to trigger the AB-BA case. */ mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); - raw_spin_lock_irq(&ctx->lock); - perf_group_detach(event); - raw_spin_unlock_irq(&ctx->lock); - perf_remove_from_context(event); + perf_remove_from_context(event, true); mutex_unlock(&ctx->mutex); free_event(event); @@ -3839,28 +3844,47 @@ unlock: static void ring_buffer_attach(struct perf_event *event, struct ring_buffer *rb) { + struct ring_buffer *old_rb = NULL; unsigned long flags; - if (!list_empty(&event->rb_entry)) - return; + if (event->rb) { + /* + * Should be impossible, we set this when removing + * event->rb_entry and wait/clear when adding event->rb_entry. + */ + WARN_ON_ONCE(event->rcu_pending); - spin_lock_irqsave(&rb->event_lock, flags); - if (list_empty(&event->rb_entry)) - list_add(&event->rb_entry, &rb->event_list); - spin_unlock_irqrestore(&rb->event_lock, flags); -} + old_rb = event->rb; + event->rcu_batches = get_state_synchronize_rcu(); + event->rcu_pending = 1; -static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb) -{ - unsigned long flags; + spin_lock_irqsave(&old_rb->event_lock, flags); + list_del_rcu(&event->rb_entry); + spin_unlock_irqrestore(&old_rb->event_lock, flags); + } - if (list_empty(&event->rb_entry)) - return; + if (event->rcu_pending && rb) { + cond_synchronize_rcu(event->rcu_batches); + event->rcu_pending = 0; + } + + if (rb) { + spin_lock_irqsave(&rb->event_lock, flags); + list_add_rcu(&event->rb_entry, &rb->event_list); + spin_unlock_irqrestore(&rb->event_lock, flags); + } + + rcu_assign_pointer(event->rb, rb); - spin_lock_irqsave(&rb->event_lock, flags); - list_del_init(&event->rb_entry); - wake_up_all(&event->waitq); - spin_unlock_irqrestore(&rb->event_lock, flags); + if (old_rb) { + ring_buffer_put(old_rb); + /* + * Since we detached before setting the new rb, so that we + * could attach the new rb, we could have missed a wakeup. + * Provide it now. + */ + wake_up_all(&event->waitq); + } } static void ring_buffer_wakeup(struct perf_event *event) @@ -3929,7 +3953,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) { struct perf_event *event = vma->vm_file->private_data; - struct ring_buffer *rb = event->rb; + struct ring_buffer *rb = ring_buffer_get(event); struct user_struct *mmap_user = rb->mmap_user; int mmap_locked = rb->mmap_locked; unsigned long size = perf_data_size(rb); @@ -3937,18 +3961,14 @@ static void perf_mmap_close(struct vm_area_struct *vma) atomic_dec(&rb->mmap_count); if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) - return; + goto out_put; - /* Detach current event from the buffer. */ - rcu_assign_pointer(event->rb, NULL); - ring_buffer_detach(event, rb); + ring_buffer_attach(event, NULL); mutex_unlock(&event->mmap_mutex); /* If there's still other mmap()s of this buffer, we're done. */ - if (atomic_read(&rb->mmap_count)) { - ring_buffer_put(rb); /* can't be last */ - return; - } + if (atomic_read(&rb->mmap_count)) + goto out_put; /* * No other mmap()s, detach from all other events that might redirect @@ -3978,11 +3998,9 @@ again: * still restart the iteration to make sure we're not now * iterating the wrong list. */ - if (event->rb == rb) { - rcu_assign_pointer(event->rb, NULL); - ring_buffer_detach(event, rb); - ring_buffer_put(rb); /* can't be last, we still have one */ - } + if (event->rb == rb) + ring_buffer_attach(event, NULL); + mutex_unlock(&event->mmap_mutex); put_event(event); @@ -4007,6 +4025,7 @@ again: vma->vm_mm->pinned_vm -= mmap_locked; free_uid(mmap_user); +out_put: ring_buffer_put(rb); /* could be last */ } @@ -4124,7 +4143,6 @@ again: vma->vm_mm->pinned_vm += extra; ring_buffer_attach(event, rb); - rcu_assign_pointer(event->rb, rb); perf_event_init_userpage(event); perf_event_update_userpage(event); @@ -5408,6 +5426,9 @@ struct swevent_htable { /* Recursion avoidance in each contexts */ int recursion[PERF_NR_CONTEXTS]; + + /* Keeps track of cpu being initialized/exited */ + bool online; }; static DEFINE_PER_CPU(struct swevent_htable, swevent_htable); @@ -5654,8 +5675,14 @@ static int perf_swevent_add(struct perf_event *event, int flags) hwc->state = !(flags & PERF_EF_START); head = find_swevent_head(swhash, event); - if (WARN_ON_ONCE(!head)) + if (!head) { + /* + * We can race with cpu hotplug code. Do not + * WARN if the cpu just got unplugged. + */ + WARN_ON_ONCE(swhash->online); return -EINVAL; + } hlist_add_head_rcu(&event->hlist_entry, head); @@ -6914,7 +6941,7 @@ err_size: static int perf_event_set_output(struct perf_event *event, struct perf_event *output_event) { - struct ring_buffer *rb = NULL, *old_rb = NULL; + struct ring_buffer *rb = NULL; int ret = -EINVAL; if (!output_event) @@ -6942,8 +6969,6 @@ set: if (atomic_read(&event->mmap_count)) goto unlock; - old_rb = event->rb; - if (output_event) { /* get the rb we want to redirect to */ rb = ring_buffer_get(output_event); @@ -6951,23 +6976,7 @@ set: goto unlock; } - if (old_rb) - ring_buffer_detach(event, old_rb); - - if (rb) - ring_buffer_attach(event, rb); - - rcu_assign_pointer(event->rb, rb); - - if (old_rb) { - ring_buffer_put(old_rb); - /* - * Since we detached before setting the new rb, so that we - * could attach the new rb, we could have missed a wakeup. - * Provide it now. - */ - wake_up_all(&event->waitq); - } + ring_buffer_attach(event, rb); ret = 0; unlock: @@ -7018,6 +7027,9 @@ SYSCALL_DEFINE5(perf_event_open, if (attr.freq) { if (attr.sample_freq > sysctl_perf_event_sample_rate) return -EINVAL; + } else { + if (attr.sample_period & (1ULL << 63)) + return -EINVAL; } /* @@ -7165,7 +7177,7 @@ SYSCALL_DEFINE5(perf_event_open, struct perf_event_context *gctx = group_leader->ctx; mutex_lock(&gctx->mutex); - perf_remove_from_context(group_leader); + perf_remove_from_context(group_leader, false); /* * Removing from the context ends up with disabled @@ -7175,7 +7187,7 @@ SYSCALL_DEFINE5(perf_event_open, perf_event__state_init(group_leader); list_for_each_entry(sibling, &group_leader->sibling_list, group_entry) { - perf_remove_from_context(sibling); + perf_remove_from_context(sibling, false); perf_event__state_init(sibling); put_ctx(gctx); } @@ -7305,7 +7317,7 @@ void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) mutex_lock(&src_ctx->mutex); list_for_each_entry_safe(event, tmp, &src_ctx->event_list, event_entry) { - perf_remove_from_context(event); + perf_remove_from_context(event, false); unaccount_event_cpu(event, src_cpu); put_ctx(src_ctx); list_add(&event->migrate_entry, &events); @@ -7367,13 +7379,7 @@ __perf_event_exit_task(struct perf_event *child_event, struct perf_event_context *child_ctx, struct task_struct *child) { - if (child_event->parent) { - raw_spin_lock_irq(&child_ctx->lock); - perf_group_detach(child_event); - raw_spin_unlock_irq(&child_ctx->lock); - } - - perf_remove_from_context(child_event); + perf_remove_from_context(child_event, !!child_event->parent); /* * It can happen that the parent exits first, and has events @@ -7724,6 +7730,8 @@ int perf_event_init_context(struct task_struct *child, int ctxn) * swapped under us. */ parent_ctx = perf_pin_task_context(parent, ctxn); + if (!parent_ctx) + return 0; /* * No need to check if parent_ctx != NULL here; since we saw @@ -7835,6 +7843,7 @@ static void perf_event_init_cpu(int cpu) struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); mutex_lock(&swhash->hlist_mutex); + swhash->online = true; if (swhash->hlist_refcount > 0) { struct swevent_hlist *hlist; @@ -7857,14 +7866,14 @@ static void perf_pmu_rotate_stop(struct pmu *pmu) static void __perf_event_exit_context(void *__info) { + struct remove_event re = { .detach_group = false }; struct perf_event_context *ctx = __info; - struct perf_event *event; perf_pmu_rotate_stop(ctx->pmu); rcu_read_lock(); - list_for_each_entry_rcu(event, &ctx->event_list, event_entry) - __perf_remove_from_context(event); + list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry) + __perf_remove_from_context(&re); rcu_read_unlock(); } @@ -7892,6 +7901,7 @@ static void perf_event_exit_cpu(int cpu) perf_event_exit_cpu_context(cpu); mutex_lock(&swhash->hlist_mutex); + swhash->online = false; swevent_hlist_release(swhash); mutex_unlock(&swhash->hlist_mutex); } diff --git a/tools/Makefile b/tools/Makefile index bcae806b0c3..9a617adc667 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -44,6 +44,9 @@ cpupower: FORCE cgroup firewire hv guest usb virtio vm net: FORCE $(call descend,$@) +liblockdep: FORCE + $(call descend,lib/lockdep) + libapikfs: FORCE $(call descend,lib/api) @@ -91,6 +94,9 @@ cpupower_clean: cgroup_clean hv_clean firewire_clean lguest_clean usb_clean virtio_clean vm_clean net_clean: $(call descend,$(@:_clean=),clean) +liblockdep_clean: + $(call descend,lib/lockdep,clean) + libapikfs_clean: $(call descend,lib/api,clean) diff --git a/tools/lib/lockdep/Makefile b/tools/lib/lockdep/Makefile index cb09d3ff8f5..bba2f5253b6 100644 --- a/tools/lib/lockdep/Makefile +++ b/tools/lib/lockdep/Makefile @@ -1,8 +1,7 @@ # file format version FILE_VERSION = 1 -MAKEFLAGS += --no-print-directory -LIBLOCKDEP_VERSION=$(shell make -sC ../../.. kernelversion) +LIBLOCKDEP_VERSION=$(shell make --no-print-directory -sC ../../.. kernelversion) # Makefiles suck: This macro sets a default value of $(2) for the # variable named by $(1), unless the variable has been set by @@ -231,7 +230,7 @@ install_lib: all_cmd install: install_lib clean: - $(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d + $(RM) *.o *~ $(TARGETS) *.a *liblockdep*.so* $(VERSION_FILES) .*.d $(RM) tags TAGS endif # skip-makefile |