#include "wrapper/uuid.h"
#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
#include "wrapper/random.h"
+#include "wrapper/tracepoint.h"
#include "lttng-events.h"
#include "lttng-tracer.h"
+#include "lttng-abi-old.h"
+
+#define METADATA_CACHE_DEFAULT_SIZE 4096
static LIST_HEAD(sessions);
static LIST_HEAD(lttng_transport_list);
+/*
+ * Protect the sessions and metadata caches.
+ */
static DEFINE_MUTEX(sessions_mutex);
static struct kmem_cache *event_cache;
struct lttng_event *event);
static
int _lttng_session_metadata_statedump(struct lttng_session *session);
+static
+void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
void synchronize_trace(void)
{
struct lttng_session *lttng_session_create(void)
{
struct lttng_session *session;
+ struct lttng_metadata_cache *metadata_cache;
mutex_lock(&sessions_mutex);
session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL);
if (!session)
- return NULL;
+ goto err;
INIT_LIST_HEAD(&session->chan);
INIT_LIST_HEAD(&session->events);
uuid_le_gen(&session->uuid);
+
+ metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
+ GFP_KERNEL);
+ if (!metadata_cache)
+ goto err_free_session;
+ metadata_cache->data = kzalloc(METADATA_CACHE_DEFAULT_SIZE,
+ GFP_KERNEL);
+ if (!metadata_cache->data)
+ goto err_free_cache;
+ metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
+ kref_init(&metadata_cache->refcount);
+ session->metadata_cache = metadata_cache;
+ INIT_LIST_HEAD(&metadata_cache->metadata_stream);
list_add(&session->list, &sessions);
mutex_unlock(&sessions_mutex);
return session;
+
+err_free_cache:
+ kfree(metadata_cache);
+err_free_session:
+ kfree(session);
+err:
+ mutex_unlock(&sessions_mutex);
+ return NULL;
+}
+
+void metadata_cache_destroy(struct kref *kref)
+{
+ struct lttng_metadata_cache *cache =
+ container_of(kref, struct lttng_metadata_cache, refcount);
+ kfree(cache->data);
+ kfree(cache);
}
void lttng_session_destroy(struct lttng_session *session)
{
struct lttng_channel *chan, *tmpchan;
struct lttng_event *event, *tmpevent;
+ struct lttng_metadata_stream *metadata_stream;
int ret;
mutex_lock(&sessions_mutex);
synchronize_trace(); /* Wait for in-flight events to complete */
list_for_each_entry_safe(event, tmpevent, &session->events, list)
_lttng_event_destroy(event);
- list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
+ list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
+ BUG_ON(chan->channel_type == METADATA_CHANNEL);
_lttng_channel_destroy(chan);
+ }
+ list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
+ _lttng_metadata_channel_hangup(metadata_stream);
+ kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
list_del(&session->list);
mutex_unlock(&sessions_mutex);
kfree(session);
{
int old;
- if (channel == channel->session->metadata)
+ if (channel->channel_type == METADATA_CHANNEL)
return -EPERM;
old = xchg(&channel->enabled, 1);
if (old)
{
int old;
- if (channel == channel->session->metadata)
+ if (channel->channel_type == METADATA_CHANNEL)
return -EPERM;
old = xchg(&channel->enabled, 0);
if (!old)
{
int old;
- if (event->chan == event->chan->session->metadata)
+ if (event->chan->channel_type == METADATA_CHANNEL)
return -EPERM;
old = xchg(&event->enabled, 1);
if (old)
{
int old;
- if (event->chan == event->chan->session->metadata)
+ if (event->chan->channel_type == METADATA_CHANNEL)
return -EPERM;
old = xchg(&event->enabled, 0);
if (!old)
void *buf_addr,
size_t subbuf_size, size_t num_subbuf,
unsigned int switch_timer_interval,
- unsigned int read_timer_interval)
+ unsigned int read_timer_interval,
+ enum channel_type channel_type)
{
struct lttng_channel *chan;
struct lttng_transport *transport = NULL;
mutex_lock(&sessions_mutex);
- if (session->been_active)
+ if (session->been_active && channel_type != METADATA_CHANNEL)
goto active; /* Refuse to add channel to active session */
transport = lttng_transport_find(transport_name);
if (!transport) {
chan->enabled = 1;
chan->ops = &transport->ops;
chan->transport = transport;
+ chan->channel_type = channel_type;
list_add(&chan->list, &session->chan);
mutex_unlock(&sessions_mutex);
return chan;
}
/*
- * Only used internally at session destruction.
+ * Only used internally at session destruction for per-cpu channels, and
+ * when metadata channel is released.
+ * Needs to be called with sessions mutex held.
*/
static
void _lttng_channel_destroy(struct lttng_channel *chan)
kfree(chan);
}
+void lttng_metadata_channel_destroy(struct lttng_channel *chan)
+{
+ BUG_ON(chan->channel_type != METADATA_CHANNEL);
+
+ /* Protect the metadata cache with the sessions_mutex. */
+ mutex_lock(&sessions_mutex);
+ _lttng_channel_destroy(chan);
+ mutex_unlock(&sessions_mutex);
+}
+EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
+
+static
+void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
+{
+ stream->finalized = 1;
+ wake_up_interruptible(&stream->read_wait);
+}
+
/*
* Supports event creation while tracing session is active.
*/
event->desc = lttng_event_get(event_param->name);
if (!event->desc)
goto register_error;
- ret = tracepoint_probe_register(event_param->name,
+ ret = kabi_2635_tracepoint_probe_register(event_param->name,
event->desc->probe_callback,
event);
if (ret)
switch (event->instrumentation) {
case LTTNG_KERNEL_TRACEPOINT:
- ret = tracepoint_probe_unregister(event->desc->name,
+ ret = kabi_2635_tracepoint_probe_unregister(event->desc->name,
event->desc->probe_callback,
event);
if (ret)
}
/*
+ * Serialize at most one packet worth of metadata into a metadata
+ * channel.
* We have exclusive access to our metadata buffer (protected by the
* sessions_mutex), so we can do racy operations such as looking for
* remaining space left in packet and write, since mutual exclusion
* protects us from concurrent writes.
*/
+int lttng_metadata_output_channel(struct lttng_channel *chan,
+ struct lttng_metadata_stream *stream)
+{
+ struct lib_ring_buffer_ctx ctx;
+ int ret = 0;
+ size_t len, reserve_len;
+
+ len = stream->metadata_cache->metadata_written -
+ stream->metadata_cache_read;
+ if (!len)
+ return 0;
+ reserve_len = min_t(size_t,
+ chan->ops->packet_avail_size(chan->chan),
+ len);
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+ sizeof(char), -1);
+ /*
+ * If reservation failed, return an error to the caller.
+ */
+ ret = chan->ops->event_reserve(&ctx, 0);
+ if (ret != 0) {
+ printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
+ goto end;
+ }
+ chan->ops->event_write(&ctx,
+ stream->metadata_cache->data + stream->metadata_cache_read,
+ reserve_len);
+ chan->ops->event_commit(&ctx);
+ stream->metadata_cache_read += reserve_len;
+ ret = reserve_len;
+
+end:
+ return ret;
+}
+
+/*
+ * Write the metadata to the metadata cache.
+ * Must be called with sessions_mutex held.
+ */
int lttng_metadata_printf(struct lttng_session *session,
const char *fmt, ...)
{
- struct lib_ring_buffer_ctx ctx;
- struct lttng_channel *chan = session->metadata;
char *str;
- int ret = 0, waitret;
- size_t len, reserve_len, pos;
+ size_t len;
va_list ap;
+ struct lttng_metadata_stream *stream;
WARN_ON_ONCE(!ACCESS_ONCE(session->active));
return -ENOMEM;
len = strlen(str);
- pos = 0;
-
- for (pos = 0; pos < len; pos += reserve_len) {
- reserve_len = min_t(size_t,
- chan->ops->packet_avail_size(chan->chan),
- len - pos);
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
- sizeof(char), -1);
- /*
- * We don't care about metadata buffer's records lost
- * count, because we always retry here. Report error if
- * we need to bail out after timeout or being
- * interrupted.
- */
- waitret = wait_event_interruptible_timeout(*chan->ops->get_writer_buf_wait_queue(chan->chan, -1),
- ({
- ret = chan->ops->event_reserve(&ctx, 0);
- ret != -ENOBUFS || !ret;
- }),
- msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
- if (!waitret || waitret == -ERESTARTSYS || ret) {
- printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
- waitret == -ERESTARTSYS ? "interrupted" :
- (ret == -ENOBUFS ? "timeout" : "I/O error"));
- if (waitret == -ERESTARTSYS)
- ret = waitret;
- goto end;
- }
- chan->ops->event_write(&ctx, &str[pos], reserve_len);
- chan->ops->event_commit(&ctx);
+ if (session->metadata_cache->metadata_written + len >
+ session->metadata_cache->cache_alloc) {
+ char *tmp_cache_realloc;
+ unsigned int tmp_cache_alloc_size;
+
+ tmp_cache_alloc_size = max_t(unsigned int,
+ session->metadata_cache->cache_alloc + len,
+ session->metadata_cache->cache_alloc << 1);
+ tmp_cache_realloc = krealloc(session->metadata_cache->data,
+ tmp_cache_alloc_size, GFP_KERNEL);
+ if (!tmp_cache_realloc)
+ goto err;
+ session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
+ session->metadata_cache->data = tmp_cache_realloc;
}
-end:
+ memcpy(session->metadata_cache->data +
+ session->metadata_cache->metadata_written,
+ str, len);
+ session->metadata_cache->metadata_written += len;
kfree(str);
- return ret;
+
+ list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
+ wake_up_interruptible(&stream->read_wait);
+
+ return 0;
+
+err:
+ kfree(str);
+ return -ENOMEM;
}
+/*
+ * Must be called with sessions_mutex held.
+ */
static
int _lttng_field_statedump(struct lttng_session *session,
const struct lttng_event_field *field)
return ret;
}
+/*
+ * Must be called with sessions_mutex held.
+ */
static
int _lttng_event_metadata_statedump(struct lttng_session *session,
struct lttng_channel *chan,
if (event->metadata_dumped || !ACCESS_ONCE(session->active))
return 0;
- if (chan == session->metadata)
+ if (chan->channel_type == METADATA_CHANNEL)
return 0;
ret = lttng_metadata_printf(session,
}
+/*
+ * Must be called with sessions_mutex held.
+ */
static
int _lttng_channel_metadata_statedump(struct lttng_session *session,
struct lttng_channel *chan)
if (chan->metadata_dumped || !ACCESS_ONCE(session->active))
return 0;
- if (chan == session->metadata)
+
+ if (chan->channel_type == METADATA_CHANNEL)
return 0;
WARN_ON_ONCE(!chan->header_type);
return ret;
}
+/*
+ * Must be called with sessions_mutex held.
+ */
static
int _lttng_stream_packet_context_declare(struct lttng_session *session)
{
"struct packet_context {\n"
" uint64_clock_monotonic_t timestamp_begin;\n"
" uint64_clock_monotonic_t timestamp_end;\n"
+ " uint64_t content_size;\n"
+ " uint64_t packet_size;\n"
" unsigned long events_discarded;\n"
- " uint32_t content_size;\n"
- " uint32_t packet_size;\n"
" uint32_t cpu_id;\n"
"};\n\n"
);
* Large header:
* id: range: 0 - 65534.
* id 65535 is reserved to indicate an extended header.
+ *
+ * Must be called with sessions_mutex held.
*/
static
int _lttng_event_header_declare(struct lttng_session *session)
/*
* Output metadata into this session's metadata buffers.
+ * Must be called with sessions_mutex held.
*/
static
int _lttng_session_metadata_statedump(struct lttng_session *session)
unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
struct lttng_channel *chan;
struct lttng_event *event;
- char hostname[__NEW_UTS_LEN + 1];
int ret = 0;
if (!ACCESS_ONCE(session->active))
return 0;
if (session->metadata_dumped)
goto skip_session;
- if (!session->metadata) {
- printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
- return -EPERM;
- }
snprintf(uuid_s, sizeof(uuid_s),
"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
if (ret)
goto end;
- rcu_read_lock();
- memcpy(hostname, task_nsproxy(current)->uts_ns->name.nodename,
- sizeof(hostname));
- rcu_read_unlock();
-
ret = lttng_metadata_printf(session,
"env {\n"
" hostname = \"%s\";\n"
" tracer_minor = %d;\n"
" tracer_patchlevel = %d;\n"
"};\n\n",
- hostname,
+ current->nsproxy->uts_ns->name.nodename,
utsname()->sysname,
utsname()->release,
utsname()->version,
projects / lttng-modules.git / blobdiff