X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-events.c;h=1d729210f83049ba3fcc7f5364988afedcfaf901;hb=cd4bd11fe2d3232089186a5b9b021b7cb504a8fb;hp=9eb2c2f2ef838998e7eedb3fee14f0dddc7b9aa2;hpb=6d2a620c03c40df6fb09429e9895f71c5d9dfa76;p=lttng-modules.git diff --git a/ltt-events.c b/ltt-events.c index 9eb2c2f2..1d729210 100644 --- a/ltt-events.c +++ b/ltt-events.c @@ -11,15 +11,26 @@ #include #include #include -#include "wrapper/symbols.h" /* for wrapper_vmalloc_sync_all() */ +#include +#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ #include "ltt-events.h" +#include "ltt-tracer.h" static LIST_HEAD(sessions); static LIST_HEAD(ltt_transport_list); static DEFINE_MUTEX(sessions_mutex); static struct kmem_cache *event_cache; -static void synchronize_trace(void) +static +int _ltt_event_metadata_statedump(struct ltt_session *session, + struct ltt_channel *chan, + struct ltt_event *event); +static +int _ltt_session_metadata_statedump(struct ltt_session *session); + + +static +void synchronize_trace(void) { synchronize_sched(); #ifdef CONFIG_PREEMPT_RT @@ -67,14 +78,34 @@ void ltt_session_destroy(struct ltt_session *session) int ltt_session_start(struct ltt_session *session) { int ret = 0; + struct ltt_channel *chan; mutex_lock(&sessions_mutex); if (session->active) { ret = -EBUSY; goto end; } + + /* + * Snapshot the number of events per channel to know the type of header + * we need to use. + */ + list_for_each_entry(chan, &session->chan, list) { + if (chan->header_type) + continue; /* don't change it if session stop/restart */ + if (chan->free_event_id < 31) + chan->header_type = 1; /* compact */ + else + chan->header_type = 2; /* large */ + } + ACCESS_ONCE(session->active) = 1; synchronize_trace(); /* Wait for in-flight events to complete */ + ret = _ltt_session_metadata_statedump(session); + if (ret) { + ACCESS_ONCE(session->active) = 0; + synchronize_trace(); /* Wait for in-flight events to complete */ + } end: mutex_unlock(&sessions_mutex); return ret; @@ -138,6 +169,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session, read_timer_interval); if (!chan->chan) goto create_error; + chan->id = session->free_chan_id++; chan->ops = &transport->ops; list_add(&chan->list, &session->chan); mutex_unlock(&sessions_mutex); @@ -167,7 +199,8 @@ void _ltt_channel_destroy(struct ltt_channel *chan) */ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, enum instrum_type itype, - void *probe, void *filter) + const struct lttng_event_desc *event_desc, + void *filter) { struct ltt_event *event; int ret; @@ -180,17 +213,13 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, * creation). Might require a hash if we have lots of events. */ list_for_each_entry(event, &chan->session->events, list) - if (!strcmp(event->name, name)) + if (!strcmp(event->desc->name, name)) goto exist; event = kmem_cache_zalloc(event_cache, GFP_KERNEL); if (!event) goto cache_error; - event->name = kmalloc(strlen(name) + 1, GFP_KERNEL); - if (!event->name) - goto name_error; - strcpy(event->name, name); event->chan = chan; - event->probe = probe; + event->desc = event_desc; event->filter = filter; event->id = chan->free_event_id++; event->itype = itype; @@ -198,20 +227,25 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, smp_wmb(); switch (itype) { case INSTRUM_TRACEPOINTS: - ret = tracepoint_probe_register(name, probe, event); + ret = tracepoint_probe_register(name, event_desc->probe_callback, + event); if (ret) goto register_error; break; default: WARN_ON_ONCE(1); } + ret = _ltt_event_metadata_statedump(chan->session, chan, event); + if (ret) + goto statedump_error; list_add(&event->list, &chan->session->events); mutex_unlock(&sessions_mutex); return event; +statedump_error: + WARN_ON_ONCE(tracepoint_probe_unregister(name, event_desc->probe_callback, + event)); register_error: - kfree(event->name); -name_error: kmem_cache_free(event_cache, event); cache_error: exist: @@ -229,7 +263,8 @@ int _ltt_event_unregister(struct ltt_event *event) switch (event->itype) { case INSTRUM_TRACEPOINTS: - ret = tracepoint_probe_unregister(event->name, event->probe, + ret = tracepoint_probe_unregister(event->desc->name, + event->desc->probe_callback, event); if (ret) return ret; @@ -245,11 +280,262 @@ int _ltt_event_unregister(struct ltt_event *event) */ void _ltt_event_destroy(struct ltt_event *event) { - kfree(event->name); + ltt_event_put(event->desc); list_del(&event->list); kmem_cache_free(event_cache, event); } +int lttng_metadata_printf(struct ltt_session *session, + const char *fmt, ...) +{ + struct lib_ring_buffer_ctx ctx; + struct ltt_channel *chan = session->metadata; + char *str; + int ret = 0, waitret; + size_t len; + va_list ap; + + WARN_ON_ONCE(!ACCESS_ONCE(session->active)); + + va_start(ap, fmt); + str = kvasprintf(GFP_KERNEL, fmt, ap); + va_end(ap); + if (!str) + return -ENOMEM; + + len = strlen(str) + 1; + lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, 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_reader_wait_queue(chan), + ({ + ret = chan->ops->event_reserve(&ctx); + ret != -ENOBUFS || !ret; + }), + msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); + if (waitret || 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, len); + chan->ops->event_commit(&ctx); +end: + kfree(str); + return ret; +} + +static +int _ltt_fields_metadata_statedump(struct ltt_session *session, + struct ltt_event *event) +{ + const struct lttng_event_desc *desc = event->desc; + int ret = 0; + int i; + + for (i = 0; i < desc->nr_fields; i++) { + const struct lttng_event_field *field = &desc->fields[i]; + + switch (field->type.atype) { + case atype_integer: + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u;%s } %s;\n", + field->type.u.basic.integer.size, + field->type.u.basic.integer.alignment, + field->type.u.basic.integer.signedness, +#ifdef __BIG_ENDIAN + field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", +#else + field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", +#endif + field->name); + break; + case atype_enum: + ret = lttng_metadata_printf(session, + " %s %s;\n", + field->type.u.basic.enumeration.name, + field->name); + break; + case atype_array: + { + const struct lttng_basic_type *elem_type; + + elem_type = &field->type.u.array.elem_type; + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u;%s } %s[%u];\n", + elem_type->u.basic.integer.size, + elem_type->u.basic.integer.alignment, + elem_type->u.basic.integer.signedness, +#ifdef __BIG_ENDIAN + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", +#else + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", +#endif + field->name, field->type.u.array.length); + break; + } + case atype_sequence: + { + const struct lttng_basic_type *elem_type; + const struct lttng_basic_type *length_type; + + elem_type = &field->type.u.sequence.elem_type; + length_type = &field->type.u.sequence.length_type; + ret = lttng_metadata_printf(session, + " integer { size = %u; align = %u; signed = %u;%s } %s[ integer { size = %u; align = %u; signed = %u;%s } ];\n", + elem_type->u.basic.integer.size, + elem_type->u.basic.integer.alignment, + elem_type->u.basic.integer.signedness, +#ifdef __BIG_ENDIAN + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", +#else + elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", +#endif + field->name, + length_type->u.basic.integer.size, + length_type->u.basic.integer.alignment, + length_type->u.basic.integer.signedness, +#ifdef __BIG_ENDIAN + length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", +#else + length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "" +#endif + ); + break; + } + + case atype_string: + ret = lttng_metadata_printf(session, + " string%s %s;\n", + field->type.u.basic.string.encoding == lttng_encode_ASCII ? + " { encoding = ASCII; }" : "", + field->name); + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + } + return ret; +} + +static +int _ltt_event_metadata_statedump(struct ltt_session *session, + struct ltt_channel *chan, + struct ltt_event *event) +{ + int ret = 0; + + if (event->metadata_dumped || !ACCESS_ONCE(session->active)) + return 0; + if (chan == session->metadata) + return 0; + + ret = lttng_metadata_printf(session, + "event {\n" + " name = %s;\n" + " id = %u;\n" + " stream_id = %u;\n" + " event.fields := struct {\n", + event->desc->name, + event->id, + event->chan->id); + if (ret) + goto end; + + ret = _ltt_fields_metadata_statedump(session, event); + if (ret) + goto end; + + /* + * LTTng space reservation can only reserve multiples of the + * byte size. + */ + ret = lttng_metadata_printf(session, + " } aligned(%u);\n" + "};\n", ltt_get_header_alignment()); + if (ret) + goto end; + + + + + event->metadata_dumped = 1; +end: + return ret; + +} + +static +int _ltt_channel_metadata_statedump(struct ltt_session *session, + struct ltt_channel *chan) +{ + int ret = 0; + + if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) + return 0; + if (chan == session->metadata) + return 0; + + WARN_ON_ONCE(!chan->header_type); + ret = lttng_metadata_printf(session, + "stream {\n" + " id = %u;\n" + " event.header := %s;\n", + "};\n", + chan->id, + chan->header_type == 1 ? "struct event_header_compact" : + "struct event_header_large"); + if (ret) + goto end; + + chan->metadata_dumped = 1; +end: + return ret; +} + +/* + * Output metadata into this session's metadata buffers. + */ +static +int _ltt_session_metadata_statedump(struct ltt_session *session) +{ + struct ltt_channel *chan; + struct ltt_event *event; + 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; + } + +skip_session: + list_for_each_entry(chan, &session->chan, list) { + ret = _ltt_channel_metadata_statedump(session, chan); + if (ret) + goto end; + } + + list_for_each_entry(event, &session->events, list) { + ret = _ltt_event_metadata_statedump(session, chan, event); + if (ret) + goto end; + } + session->metadata_dumped = 1; +end: + return ret; +} + /** * ltt_transport_register - LTT transport registration * @transport: transport structure @@ -289,7 +575,6 @@ void ltt_transport_unregister(struct ltt_transport *transport) } EXPORT_SYMBOL_GPL(ltt_transport_unregister); - static int __init ltt_events_init(void) { int ret; @@ -297,16 +582,11 @@ static int __init ltt_events_init(void) event_cache = KMEM_CACHE(ltt_event, 0); if (!event_cache) return -ENOMEM; - ret = ltt_probes_init(); - if (ret) - goto error; ret = ltt_debugfs_abi_init(); if (ret) goto error_abi; return 0; error_abi: - ltt_probes_exit(); -error: kmem_cache_destroy(event_cache); return ret; } @@ -318,7 +598,6 @@ static void __exit ltt_events_exit(void) struct ltt_session *session, *tmpsession; ltt_debugfs_abi_exit(); - ltt_probes_exit(); list_for_each_entry_safe(session, tmpsession, &sessions, list) ltt_session_destroy(session); kmem_cache_destroy(event_cache);