diff options
Diffstat (limited to 'tools/tracing/rtla/src/trace.c')
| -rw-r--r-- | tools/tracing/rtla/src/trace.c | 172 |
1 files changed, 106 insertions, 66 deletions
diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c index 170a706248ab..e407447773d0 100644 --- a/tools/tracing/rtla/src/trace.c +++ b/tools/tracing/rtla/src/trace.c @@ -2,7 +2,6 @@ #define _GNU_SOURCE #include <sys/sendfile.h> #include <tracefs.h> -#include <signal.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> @@ -74,6 +73,11 @@ int save_trace_to_file(struct tracefs_instance *inst, const char *filename) char buffer[4096]; int out_fd, in_fd; int retval = -1; + ssize_t n_read; + ssize_t n_written; + + if (!inst || !filename) + return 0; in_fd = tracefs_instance_file_open(inst, file, O_RDONLY); if (in_fd < 0) { @@ -81,21 +85,37 @@ int save_trace_to_file(struct tracefs_instance *inst, const char *filename) return -1; } + printf(" Saving trace to %s\n", filename); out_fd = creat(filename, mode); if (out_fd < 0) { err_msg("Failed to create output file %s\n", filename); goto out_close_in; } - do { - retval = read(in_fd, buffer, sizeof(buffer)); - if (retval <= 0) + for (;;) { + n_read = read(in_fd, buffer, sizeof(buffer)); + if (n_read < 0) { + if (errno == EINTR) + continue; + err_msg("Error reading trace file: %s\n", strerror(errno)); goto out_close; - - retval = write(out_fd, buffer, retval); - if (retval < 0) - goto out_close; - } while (retval > 0); + } + if (n_read == 0) + break; + + n_written = 0; + while (n_written < n_read) { + const ssize_t w = write(out_fd, buffer + n_written, n_read - n_written); + + if (w < 0) { + if (errno == EINTR) + continue; + err_msg("Error writing trace file: %s\n", strerror(errno)); + goto out_close; + } + n_written += w; + } + } retval = 0; out_close: @@ -118,6 +138,8 @@ collect_registered_events(struct tep_event *event, struct tep_record *record, struct trace_instance *trace = context; struct trace_seq *s = trace->seq; + trace->processed_events++; + if (!event->handler) return 0; @@ -127,6 +149,31 @@ collect_registered_events(struct tep_event *event, struct tep_record *record, } /* + * collect_missed_events - record number of missed events + * + * If rtla cannot keep up with events generated by tracer, events are going + * to fall out of the ring buffer. + * Collect how many events were missed so it can be reported to the user. + */ +static int +collect_missed_events(struct tep_event *event, struct tep_record *record, + int cpu, void *context) +{ + struct trace_instance *trace = context; + + if (trace->missed_events == UINT64_MAX) + return 0; + + if (record->missed_events > 0) + trace->missed_events += record->missed_events; + else + /* Events missed but no data on how many */ + trace->missed_events = UINT64_MAX; + + return 0; +} + +/* * trace_instance_destroy - destroy and free a rtla trace instance */ void trace_instance_destroy(struct trace_instance *trace) @@ -161,9 +208,7 @@ void trace_instance_destroy(struct trace_instance *trace) */ int trace_instance_init(struct trace_instance *trace, char *tool_name) { - trace->seq = calloc(1, sizeof(*trace->seq)); - if (!trace->seq) - goto out_err; + trace->seq = calloc_fatal(1, sizeof(*trace->seq)); trace_seq_init(trace->seq); @@ -181,6 +226,17 @@ int trace_instance_init(struct trace_instance *trace, char *tool_name) */ tracefs_trace_off(trace->inst); + /* + * Collect the number of events missed due to tracefs buffer + * overflow. + */ + trace->missed_events = 0; + tracefs_follow_missed_events(trace->inst, + collect_missed_events, + trace); + + trace->processed_events = 0; + return 0; out_err: @@ -197,6 +253,14 @@ int trace_instance_start(struct trace_instance *trace) } /* + * trace_instance_stop - stop tracing a given rtla instance + */ +int trace_instance_stop(struct trace_instance *trace) +{ + return tracefs_trace_off(trace->inst); +} + +/* * trace_events_free - free a list of trace events */ static void trace_events_free(struct trace_events *events) @@ -225,15 +289,9 @@ struct trace_events *trace_event_alloc(const char *event_string) { struct trace_events *tevent; - tevent = calloc(1, sizeof(*tevent)); - if (!tevent) - return NULL; + tevent = calloc_fatal(1, sizeof(*tevent)); - tevent->system = strdup(event_string); - if (!tevent->system) { - free(tevent); - return NULL; - } + tevent->system = strdup_fatal(event_string); tevent->event = strstr(tevent->system, ":"); if (tevent->event) { @@ -247,31 +305,23 @@ struct trace_events *trace_event_alloc(const char *event_string) /* * trace_event_add_filter - record an event filter */ -int trace_event_add_filter(struct trace_events *event, char *filter) +void trace_event_add_filter(struct trace_events *event, char *filter) { if (event->filter) free(event->filter); - event->filter = strdup(filter); - if (!event->filter) - return 1; - - return 0; + event->filter = strdup_fatal(filter); } /* * trace_event_add_trigger - record an event trigger action */ -int trace_event_add_trigger(struct trace_events *event, char *trigger) +void trace_event_add_trigger(struct trace_events *event, char *trigger) { if (event->trigger) free(event->trigger); - event->trigger = strdup(trigger); - if (!event->trigger) - return 1; - - return 0; + event->trigger = strdup_fatal(trigger); } /* @@ -280,7 +330,7 @@ int trace_event_add_trigger(struct trace_events *event, char *trigger) static void trace_event_disable_filter(struct trace_instance *instance, struct trace_events *tevent) { - char filter[1024]; + char filter[MAX_PATH]; int retval; if (!tevent->filter) @@ -292,7 +342,7 @@ static void trace_event_disable_filter(struct trace_instance *instance, debug_msg("Disabling %s:%s filter %s\n", tevent->system, tevent->event ? : "*", tevent->filter); - snprintf(filter, 1024, "!%s\n", tevent->filter); + snprintf(filter, ARRAY_SIZE(filter), "!%s\n", tevent->filter); retval = tracefs_event_file_write(instance->inst, tevent->system, tevent->event, "filter", filter); @@ -309,10 +359,11 @@ static void trace_event_disable_filter(struct trace_instance *instance, static void trace_event_save_hist(struct trace_instance *instance, struct trace_events *tevent) { - int retval, index, out_fd; + size_t index, hist_len; mode_t mode = 0644; - char path[1024]; + char path[MAX_PATH]; char *hist; + int out_fd; if (!tevent) return; @@ -322,11 +373,10 @@ static void trace_event_save_hist(struct trace_instance *instance, return; /* is this a hist: trigger? */ - retval = strncmp(tevent->trigger, "hist:", strlen("hist:")); - if (retval) + if (!str_has_prefix(tevent->trigger, "hist:")) return; - snprintf(path, 1024, "%s_%s_hist.txt", tevent->system, tevent->event); + snprintf(path, ARRAY_SIZE(path), "%s_%s_hist.txt", tevent->system, tevent->event); printf(" Saving event %s:%s hist to %s\n", tevent->system, tevent->event, path); @@ -343,9 +393,18 @@ static void trace_event_save_hist(struct trace_instance *instance, } index = 0; + hist_len = strlen(hist); do { - index += write(out_fd, &hist[index], strlen(hist) - index); - } while (index < strlen(hist)); + const ssize_t written = write(out_fd, &hist[index], hist_len - index); + + if (written < 0) { + if (errno == EINTR) + continue; + err_msg(" Error writing hist file: %s\n", strerror(errno)); + break; + } + index += written; + } while (index < hist_len); free(hist); out_close: @@ -358,7 +417,7 @@ out_close: static void trace_event_disable_trigger(struct trace_instance *instance, struct trace_events *tevent) { - char trigger[1024]; + char trigger[MAX_PATH]; int retval; if (!tevent->trigger) @@ -372,7 +431,7 @@ static void trace_event_disable_trigger(struct trace_instance *instance, trace_event_save_hist(instance, tevent); - snprintf(trigger, 1024, "!%s\n", tevent->trigger); + snprintf(trigger, ARRAY_SIZE(trigger), "!%s\n", tevent->trigger); retval = tracefs_event_file_write(instance->inst, tevent->system, tevent->event, "trigger", trigger); @@ -411,7 +470,7 @@ void trace_events_disable(struct trace_instance *instance, static int trace_event_enable_filter(struct trace_instance *instance, struct trace_events *tevent) { - char filter[1024]; + char filter[MAX_PATH]; int retval; if (!tevent->filter) @@ -423,7 +482,7 @@ static int trace_event_enable_filter(struct trace_instance *instance, return 1; } - snprintf(filter, 1024, "%s\n", tevent->filter); + snprintf(filter, ARRAY_SIZE(filter), "%s\n", tevent->filter); debug_msg("Enabling %s:%s filter %s\n", tevent->system, tevent->event ? : "*", tevent->filter); @@ -446,7 +505,7 @@ static int trace_event_enable_filter(struct trace_instance *instance, static int trace_event_enable_trigger(struct trace_instance *instance, struct trace_events *tevent) { - char trigger[1024]; + char trigger[MAX_PATH]; int retval; if (!tevent->trigger) @@ -458,7 +517,7 @@ static int trace_event_enable_trigger(struct trace_instance *instance, return 1; } - snprintf(trigger, 1024, "%s\n", tevent->trigger); + snprintf(trigger, ARRAY_SIZE(trigger), "%s\n", tevent->trigger); debug_msg("Enabling %s:%s trigger %s\n", tevent->system, tevent->event ? : "*", tevent->trigger); @@ -522,25 +581,6 @@ void trace_events_destroy(struct trace_instance *instance, trace_events_free(events); } -int trace_is_off(struct trace_instance *tool, struct trace_instance *trace) -{ - /* - * The tool instance is always present, it is the one used to collect - * data. - */ - if (!tracefs_trace_is_on(tool->inst)) - return 1; - - /* - * The trace instance is only enabled when -t is set. IOW, when the system - * is tracing. - */ - if (trace && !tracefs_trace_is_on(trace->inst)) - return 1; - - return 0; -} - /* * trace_set_buffer_size - set the per-cpu tracing buffer size. */ |