X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-perf-counters.c;h=a6ff55b678d472d29fb157f7b0527918432121e2;hb=HEAD;hp=0b8f9fa2ee27bd1646d3785bc58668ea069063f7;hpb=649fb6b3dda80cf5e321e2e6f29cfc398701f78d;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-perf-counters.c b/liblttng-ust/lttng-context-perf-counters.c
deleted file mode 100644
index 0b8f9fa2..00000000
--- a/liblttng-ust/lttng-context-perf-counters.c
+++ /dev/null
@@ -1,518 +0,0 @@
-/*
- * lttng-context-perf-counters.c
- *
- * LTTng UST performance monitoring counters (perf-counters) integration.
- *
- * Copyright (C) 2009-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <sys/types.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdbool.h>
-#include <sys/mman.h>
-#include <sys/syscall.h>
-#include <linux/perf_event.h>
-#include <lttng/ust-events.h>
-#include <lttng/ust-tracer.h>
-#include <lttng/ringbuffer-config.h>
-#include <urcu/system.h>
-#include <urcu/arch.h>
-#include <urcu/rculist.h>
-#include <helper.h>
-#include <urcu/ref.h>
-#include <usterr-signal-safe.h>
-#include <signal.h>
-#include "lttng-tracer-core.h"
-
-/*
- * We use a global perf counter key and iterate on per-thread RCU lists
- * of fields in the fast path, even though this is not strictly speaking
- * what would provide the best fast-path complexity, to ensure teardown
- * of sessions vs thread exit is handled racelessly.
- *
- * Updates and traversals of thread_list are protected by UST lock.
- * Updates to rcu_field_list are protected by UST lock.
- */
-
-struct lttng_perf_counter_thread_field {
-	struct lttng_perf_counter_field *field;	/* Back reference */
-	struct perf_event_mmap_page *pc;
-	struct cds_list_head thread_field_node;	/* Per-field list of thread fields (node) */
-	struct cds_list_head rcu_field_node;	/* RCU per-thread list of fields (node) */
-	int fd;					/* Perf FD */
-};
-
-struct lttng_perf_counter_thread {
-	struct cds_list_head rcu_field_list;	/* RCU per-thread list of fields */
-};
-
-struct lttng_perf_counter_field {
-	struct perf_event_attr attr;
-	struct cds_list_head thread_field_list;	/* Per-field list of thread fields */
-};
-
-static pthread_key_t perf_counter_key;
-
-static
-size_t perf_counter_get_size(struct lttng_ctx_field *field, size_t offset)
-{
-	size_t size = 0;
-
-	size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
-	size += sizeof(uint64_t);
-	return size;
-}
-
-#if defined(__x86_64__) || defined(__i386__)
-
-static
-uint64_t rdpmc(unsigned int counter)
-{
-	unsigned int low, high;
-
-	asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));
-
-	return low | ((uint64_t) high) << 32;
-}
-
-static bool arch_perf_use_read(void)
-{
-	return false;
-}
-
-static
-uint64_t read_perf_counter(
-		struct lttng_perf_counter_thread_field *thread_field)
-{
-	uint32_t seq, idx;
-	uint64_t count;
-	struct perf_event_mmap_page *pc = thread_field->pc;
-
-	if (caa_unlikely(!pc))
-		return 0;
-
-	do {
-		seq = CMM_LOAD_SHARED(pc->lock);
-		cmm_barrier();
-
-		idx = pc->index;
-		if (idx)
-			count = pc->offset + rdpmc(idx - 1);
-		else
-			count = 0;
-
-		cmm_barrier();
-	} while (CMM_LOAD_SHARED(pc->lock) != seq);
-
-	return count;
-}
-
-#elif defined (__ARM_ARCH_7A__)
-
-static bool arch_perf_use_read(void)
-{
-	return true;
-}
-
-static
-uint64_t read_perf_counter(
-		struct lttng_perf_counter_thread_field *thread_field)
-{
-	uint64_t count;
-
-	if (caa_unlikely(thread_field->fd < 0))
-		return 0;
-
-	if (caa_unlikely(read(thread_field->fd, &count, sizeof(count))
-				< sizeof(count)))
-		return 0;
-
-	return count;
-}
-
-#else /* defined(__x86_64__) || defined(__i386__) || defined(__ARM_ARCH_7A__) */
-
-#error "Perf event counters are only supported on x86 and ARMv7 so far."
-
-#endif /* #else defined(__x86_64__) || defined(__i386__) || defined(__ARM_ARCH_7A__) */
-
-static
-int sys_perf_event_open(struct perf_event_attr *attr,
-		pid_t pid, int cpu, int group_fd,
-		unsigned long flags)
-{
-	return syscall(SYS_perf_event_open, attr, pid, cpu,
-			group_fd, flags);
-}
-
-static
-int open_perf_fd(struct perf_event_attr *attr)
-{
-	int fd;
-
-	fd = sys_perf_event_open(attr, 0, -1, -1, 0);
-	if (fd < 0)
-		return -1;
-
-	return fd;
-}
-
-static
-void close_perf_fd(int fd)
-{
-	int ret;
-
-	if (fd < 0)
-		return;
-
-	ret = close(fd);
-	if (ret) {
-		perror("Error closing LTTng-UST perf memory mapping FD");
-	}
-}
-
-static
-struct perf_event_mmap_page *setup_perf(
-		struct lttng_perf_counter_thread_field *thread_field)
-{
-	void *perf_addr;
-
-	perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page),
-			PROT_READ, MAP_SHARED, thread_field->fd, 0);
-	if (perf_addr == MAP_FAILED)
-		perf_addr = NULL;
-
-	if (!arch_perf_use_read()) {
-		close_perf_fd(thread_field->fd);
-		thread_field->fd = -1;
-	}
-
-	return perf_addr;
-}
-
-static
-void unmap_perf_page(struct perf_event_mmap_page *pc)
-{
-	int ret;
-
-	if (!pc)
-		return;
-	ret = munmap(pc, sizeof(struct perf_event_mmap_page));
-	if (ret < 0) {
-		PERROR("Error in munmap");
-		abort();
-	}
-}
-
-static
-struct lttng_perf_counter_thread *alloc_perf_counter_thread(void)
-{
-	struct lttng_perf_counter_thread *perf_thread;
-	sigset_t newmask, oldmask;
-	int ret;
-
-	ret = sigfillset(&newmask);
-	if (ret)
-		abort();
-	ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
-	if (ret)
-		abort();
-	/* Check again with signals disabled */
-	perf_thread = pthread_getspecific(perf_counter_key);
-	if (perf_thread)
-		goto skip;
-	perf_thread = zmalloc(sizeof(*perf_thread));
-	if (!perf_thread)
-		abort();
-	CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list);
-	ret = pthread_setspecific(perf_counter_key, perf_thread);
-	if (ret)
-		abort();
-skip:
-	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
-	if (ret)
-		abort();
-	return perf_thread;
-}
-
-static
-struct lttng_perf_counter_thread_field *
-	add_thread_field(struct lttng_perf_counter_field *perf_field,
-		struct lttng_perf_counter_thread *perf_thread)
-{
-	struct lttng_perf_counter_thread_field *thread_field;
-	sigset_t newmask, oldmask;
-	int ret;
-
-	ret = sigfillset(&newmask);
-	if (ret)
-		abort();
-	ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
-	if (ret)
-		abort();
-	/* Check again with signals disabled */
-	cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list,
-			rcu_field_node) {
-		if (thread_field->field == perf_field)
-			goto skip;
-	}
-	thread_field = zmalloc(sizeof(*thread_field));
-	if (!thread_field)
-		abort();
-	thread_field->field = perf_field;
-	thread_field->fd = open_perf_fd(&perf_field->attr);
-	if (thread_field->fd >= 0)
-		thread_field->pc = setup_perf(thread_field);
-	/*
-	 * Note: thread_field->pc can be NULL if setup_perf() fails.
-	 * Also, thread_field->fd can be -1 if open_perf_fd() fails.
-	 */
-	ust_lock_nocheck();
-	cds_list_add_rcu(&thread_field->rcu_field_node,
-			&perf_thread->rcu_field_list);
-	cds_list_add(&thread_field->thread_field_node,
-			&perf_field->thread_field_list);
-	ust_unlock();
-skip:
-	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
-	if (ret)
-		abort();
-	return thread_field;
-}
-
-static
-struct lttng_perf_counter_thread_field *
-		get_thread_field(struct lttng_perf_counter_field *field)
-{
-	struct lttng_perf_counter_thread *perf_thread;
-	struct lttng_perf_counter_thread_field *thread_field;
-
-	perf_thread = pthread_getspecific(perf_counter_key);
-	if (!perf_thread)
-		perf_thread = alloc_perf_counter_thread();
-	cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list,
-			rcu_field_node) {
-		if (thread_field->field == field)
-			return thread_field;
-	}
-	/* perf_counter_thread_field not found, need to add one */
-	return add_thread_field(field, perf_thread);
-}
-
-static
-uint64_t wrapper_perf_counter_read(struct lttng_ctx_field *field)
-{
-	struct lttng_perf_counter_field *perf_field;
-	struct lttng_perf_counter_thread_field *perf_thread_field;
-
-	perf_field = field->u.perf_counter;
-	perf_thread_field = get_thread_field(perf_field);
-	return read_perf_counter(perf_thread_field);
-}
-
-static
-void perf_counter_record(struct lttng_ctx_field *field,
-		 struct lttng_ust_lib_ring_buffer_ctx *ctx,
-		 struct lttng_channel *chan)
-{
-	uint64_t value;
-
-	value = wrapper_perf_counter_read(field);
-	lib_ring_buffer_align_ctx(ctx, lttng_alignof(value));
-	chan->ops->event_write(ctx, &value, sizeof(value));
-}
-
-static
-void perf_counter_get_value(struct lttng_ctx_field *field,
-		struct lttng_ctx_value *value)
-{
-	uint64_t v;
-
-	v = wrapper_perf_counter_read(field);
-	value->u.s64 = v;
-}
-
-/* Called with UST lock held */
-static
-void lttng_destroy_perf_thread_field(
-		struct lttng_perf_counter_thread_field *thread_field)
-{
-	close_perf_fd(thread_field->fd);
-	unmap_perf_page(thread_field->pc);
-	cds_list_del_rcu(&thread_field->rcu_field_node);
-	cds_list_del(&thread_field->thread_field_node);
-	free(thread_field);
-}
-
-static
-void lttng_destroy_perf_thread_key(void *_key)
-{
-	struct lttng_perf_counter_thread *perf_thread = _key;
-	struct lttng_perf_counter_thread_field *pos, *p;
-
-	ust_lock_nocheck();
-	cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list,
-			rcu_field_node)
-		lttng_destroy_perf_thread_field(pos);
-	ust_unlock();
-	free(perf_thread);
-}
-
-/* Called with UST lock held */
-static
-void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
-{
-	struct lttng_perf_counter_field *perf_field;
-	struct lttng_perf_counter_thread_field *pos, *p;
-
-	free((char *) field->event_field.name);
-	perf_field = field->u.perf_counter;
-	/*
-	 * This put is performed when no threads can concurrently
-	 * perform a "get" concurrently, thanks to urcu-bp grace
-	 * period.
-	 */
-	cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list,
-			thread_field_node)
-		lttng_destroy_perf_thread_field(pos);
-	free(perf_field);
-}
-
-#ifdef __ARM_ARCH_7A__
-
-static
-int perf_get_exclude_kernel(void)
-{
-	return 0;
-}
-
-#else /* __ARM_ARCH_7A__ */
-
-static
-int perf_get_exclude_kernel(void)
-{
-	return 1;
-}
-
-#endif /* __ARM_ARCH_7A__ */
-
-/* Called with UST lock held */
-int lttng_add_perf_counter_to_ctx(uint32_t type,
-				uint64_t config,
-				const char *name,
-				struct lttng_ctx **ctx)
-{
-	struct lttng_ctx_field *field;
-	struct lttng_perf_counter_field *perf_field;
-	char *name_alloc;
-	int ret;
-
-	name_alloc = strdup(name);
-	if (!name_alloc) {
-		ret = -ENOMEM;
-		goto name_alloc_error;
-	}
-	perf_field = zmalloc(sizeof(*perf_field));
-	if (!perf_field) {
-		ret = -ENOMEM;
-		goto perf_field_alloc_error;
-	}
-	field = lttng_append_context(ctx);
-	if (!field) {
-		ret = -ENOMEM;
-		goto append_context_error;
-	}
-	if (lttng_find_context(*ctx, name_alloc)) {
-		ret = -EEXIST;
-		goto find_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(uint64_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.alignment =
-			lttng_alignof(uint64_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.signedness =
-			lttng_is_signed_type(uint64_t);
-	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->get_size = perf_counter_get_size;
-	field->record = perf_counter_record;
-	field->get_value = perf_counter_get_value;
-
-	perf_field->attr.type = type;
-	perf_field->attr.config = config;
-	perf_field->attr.exclude_kernel = perf_get_exclude_kernel();
-	CDS_INIT_LIST_HEAD(&perf_field->thread_field_list);
-	field->u.perf_counter = perf_field;
-
-	/* Ensure that this perf counter can be used in this process. */
-	ret = open_perf_fd(&perf_field->attr);
-	if (ret < 0) {
-		ret = -ENODEV;
-		goto setup_error;
-	}
-	close_perf_fd(ret);
-
-	/*
-	 * Contexts can only be added before tracing is started, so we
-	 * don't have to synchronize against concurrent threads using
-	 * the field here.
-	 */
-
-	lttng_context_update(*ctx);
-	return 0;
-
-setup_error:
-find_error:
-	lttng_remove_context_field(ctx, field);
-append_context_error:
-	free(perf_field);
-perf_field_alloc_error:
-	free(name_alloc);
-name_alloc_error:
-	return ret;
-}
-
-int lttng_perf_counter_init(void)
-{
-	int ret;
-
-	ret = pthread_key_create(&perf_counter_key,
-			lttng_destroy_perf_thread_key);
-	if (ret)
-		ret = -ret;
-	return ret;
-}
-
-void lttng_perf_counter_exit(void)
-{
-	int ret;
-
-	ret = pthread_key_delete(perf_counter_key);
-	if (ret) {
-		errno = ret;
-		PERROR("Error in pthread_key_delete");
-	}
-}