X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-context-perf-counters.c;h=9fa6db50b8735e136fd666a51018fd0c47bbe151;hb=b53047135828b997a4eeb2cae7344cb169aa9c8c;hp=ede510ecc16c726dfe76688518a1c57aa1fe816e;hpb=4c7c514aab9e3a6ade7ced2015f54e89d2e84b1b;p=lttng-modules.git diff --git a/lttng-context-perf-counters.c b/lttng-context-perf-counters.c index ede510ec..9fa6db50 100644 --- a/lttng-context-perf-counters.c +++ b/lttng-context-perf-counters.c @@ -1,10 +1,10 @@ -/* - * (C) Copyright 2009-2011 - - * Mathieu Desnoyers +/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) + * + * lttng-context-perf-counters.c * * LTTng performance monitoring counters (perf-counters) integration module. * - * Dual LGPL v2.1/GPL v2 license. + * Copyright (C) 2009-2012 Mathieu Desnoyers */ #include @@ -12,24 +12,18 @@ #include #include #include -#include "ltt-events.h" -#include "wrapper/ringbuffer/frontend_types.h" -#include "wrapper/vmalloc.h" -#include "ltt-tracer.h" - -/* - * TODO: Add CPU hotplug support. - */ - -static DEFINE_MUTEX(perf_counter_mutex); -static LIST_HEAD(perf_counter_contexts); +#include +#include +#include +#include +#include static size_t perf_counter_get_size(size_t offset) { size_t size = 0; - size += lib_ring_buffer_align(offset, ltt_alignof(uint64_t)); + size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); size += sizeof(uint64_t); return size; } @@ -37,20 +31,35 @@ size_t perf_counter_get_size(size_t offset) static void perf_counter_record(struct lttng_ctx_field *field, struct lib_ring_buffer_ctx *ctx, - struct ltt_channel *chan) + struct lttng_channel *chan) { struct perf_event *event; uint64_t value; - event = field->u.perf_counter.e[ctx->cpu]; - event->pmu->read(event); - value = local64_read(&event->count); - lib_ring_buffer_align_ctx(ctx, ltt_alignof(value)); + event = field->u.perf_counter->e[ctx->cpu]; + if (likely(event)) { + if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) { + value = 0; + } else { + event->pmu->read(event); + value = local64_read(&event->count); + } + } else { + /* + * Perf chooses not to be clever and not to support enabling a + * perf counter before the cpu is brought up. Therefore, we need + * to support having events coming (e.g. scheduler events) + * before the counter is setup. Write an arbitrary 0 in this + * case. + */ + value = 0; + } + lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); chan->ops->event_write(ctx, &value, sizeof(value)); } static -void overflow_callback(struct perf_event *event, int nmi, +void overflow_callback(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) { @@ -59,17 +68,61 @@ void overflow_callback(struct perf_event *event, int nmi, static void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field) { - struct perf_event **events = field->u.perf_counter.e; - int cpu; - - mutex_lock(&perf_counter_mutex); - list_del(&field->u.perf_counter.head); - for_each_online_cpu(cpu) - perf_event_release_kernel(events[cpu]); - mutex_unlock(&perf_counter_mutex); + struct perf_event **events = field->u.perf_counter->e; + + { + int ret; + + ret = cpuhp_state_remove_instance(lttng_hp_online, + &field->u.perf_counter->cpuhp_online.node); + WARN_ON(ret); + ret = cpuhp_state_remove_instance(lttng_hp_prepare, + &field->u.perf_counter->cpuhp_prepare.node); + WARN_ON(ret); + } kfree(field->event_field.name); - kfree(field->u.perf_counter.attr); - kfree(events); + kfree(field->u.perf_counter->attr); + kvfree(events); + kfree(field->u.perf_counter); +} + +int lttng_cpuhp_perf_counter_online(unsigned int cpu, + struct lttng_cpuhp_node *node) +{ + struct lttng_perf_counter_field *perf_field = + container_of(node, struct lttng_perf_counter_field, + cpuhp_online); + struct perf_event **events = perf_field->e; + struct perf_event_attr *attr = perf_field->attr; + struct perf_event *pevent; + + pevent = perf_event_create_kernel_counter(attr, + cpu, NULL, overflow_callback, NULL); + if (!pevent || IS_ERR(pevent)) + return -EINVAL; + if (pevent->state == PERF_EVENT_STATE_ERROR) { + perf_event_release_kernel(pevent); + return -EINVAL; + } + barrier(); /* Create perf counter before setting event */ + events[cpu] = pevent; + return 0; +} + +int lttng_cpuhp_perf_counter_dead(unsigned int cpu, + struct lttng_cpuhp_node *node) +{ + struct lttng_perf_counter_field *perf_field = + container_of(node, struct lttng_perf_counter_field, + cpuhp_prepare); + struct perf_event **events = perf_field->e; + struct perf_event *pevent; + + pevent = events[cpu]; + events[cpu] = NULL; + barrier(); /* NULLify event before perf counter teardown */ + perf_event_release_kernel(pevent); + return 0; } int lttng_add_perf_counter_to_ctx(uint32_t type, @@ -78,17 +131,17 @@ int lttng_add_perf_counter_to_ctx(uint32_t type, struct lttng_ctx **ctx) { struct lttng_ctx_field *field; + struct lttng_perf_counter_field *perf_field; struct perf_event **events; struct perf_event_attr *attr; int ret; - int cpu; char *name_alloc; - events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL); + events = kvzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL); if (!events) return -ENOMEM; - attr = kzalloc(sizeof(*field->u.perf_counter.attr), GFP_KERNEL); + attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL); if (!attr) { ret = -ENOMEM; goto error_attr; @@ -100,61 +153,77 @@ int lttng_add_perf_counter_to_ctx(uint32_t type, attr->pinned = 1; attr->disabled = 0; - mutex_lock(&perf_counter_mutex); - - for_each_online_cpu(cpu) { - events[cpu] = perf_event_create_kernel_counter(attr, - cpu, NULL, overflow_callback); - if (!events[cpu]) { - ret = -EINVAL; - goto error; - } + perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL); + if (!perf_field) { + ret = -ENOMEM; + goto error_alloc_perf_field; } + perf_field->e = events; + perf_field->attr = attr; name_alloc = kstrdup(name, GFP_KERNEL); - if (!name_alloc) + if (!name_alloc) { + ret = -ENOMEM; goto name_alloc_error; + } field = lttng_append_context(ctx); if (!field) { ret = -ENOMEM; - goto error; + goto append_context_error; + } + if (lttng_find_context(*ctx, name_alloc)) { + ret = -EEXIST; + goto find_error; } + + perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS; + ret = cpuhp_state_add_instance(lttng_hp_prepare, + &perf_field->cpuhp_prepare.node); + if (ret) + goto cpuhp_prepare_error; + + perf_field->cpuhp_online.component = LTTNG_CONTEXT_PERF_COUNTERS; + ret = cpuhp_state_add_instance(lttng_hp_online, + &perf_field->cpuhp_online.node); + if (ret) + goto cpuhp_online_error; + field->destroy = lttng_destroy_perf_counter_field; field->event_field.name = name_alloc; field->event_field.type.atype = atype_integer; - field->event_field.type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT; - field->event_field.type.u.basic.integer.alignment = ltt_alignof(unsigned long) * CHAR_BIT; - field->event_field.type.u.basic.integer.signedness = is_signed_type(unsigned long); - field->event_field.type.u.basic.integer.reverse_byte_order = 0; - field->event_field.type.u.basic.integer.base = 10; - field->event_field.type.u.basic.integer.encoding = lttng_encode_none; + field->event_field.type.u.integer.size = sizeof(uint64_t) * CHAR_BIT; + field->event_field.type.u.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT; + field->event_field.type.u.integer.signedness = lttng_is_signed_type(uint64_t); + field->event_field.type.u.integer.reverse_byte_order = 0; + field->event_field.type.u.integer.base = 10; + field->event_field.type.u.integer.encoding = lttng_encode_none; field->get_size = perf_counter_get_size; field->record = perf_counter_record; - field->u.perf_counter.e = events; - field->u.perf_counter.attr = attr; - - list_add(&field->u.perf_counter.head, &perf_counter_contexts); - mutex_unlock(&perf_counter_mutex); + field->u.perf_counter = perf_field; + lttng_context_update(*ctx); - wrapper_vmalloc_sync_all(); return 0; -error: +cpuhp_online_error: + { + int remove_ret; + + remove_ret = cpuhp_state_remove_instance(lttng_hp_prepare, + &perf_field->cpuhp_prepare.node); + WARN_ON(remove_ret); + } +cpuhp_prepare_error: +find_error: + lttng_remove_context_field(ctx, field); +append_context_error: kfree(name_alloc); name_alloc_error: - for_each_online_cpu(cpu) { - if (events[cpu]) - perf_event_release_kernel(events[cpu]); - } - mutex_unlock(&perf_counter_mutex); + kfree(perf_field); +error_alloc_perf_field: kfree(attr); error_attr: - kfree(events); + kvfree(events); return ret; } - -MODULE_LICENSE("GPL and additional rights"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");