diff options
| -rw-r--r-- | docs/tracing.txt | 9 | ||||
| -rw-r--r-- | trace/simple.c | 19 | ||||
| -rw-r--r-- | trace/stderr.c | 17 |
3 files changed, 41 insertions, 4 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt index 95ca16c05d..ea29f2c222 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -132,12 +132,19 @@ This functionality is also provided through monitor commands: means disabled. * trace-event NAME on|off - Enable/disable a given trace event. + Enable/disable a given trace event or a group of events having common prefix + through wildcard. The "-trace events=<file>" command line argument can be used to enable the events listed in <file> from the very beginning of the program. This file must contain one event name per line. +A basic wildcard matching is supported in both the monitor command "trace +-event" and the events list file. That means you can enable/disable the events +having a common prefix in a batch. For example, virtio-blk trace events could +be enabled using: + trace-event virtio_blk_* on + == Trace backends == The "tracetool" script automates tedious trace event code generation and also diff --git a/trace/simple.c b/trace/simple.c index b639dda806..6339152d27 100644 --- a/trace/simple.c +++ b/trace/simple.c @@ -324,14 +324,29 @@ void trace_print_events(FILE *stream, fprintf_function stream_printf) bool trace_event_set_state(const char *name, bool state) { unsigned int i; - + unsigned int len; + bool wildcard = false; + bool matched = false; + + len = strlen(name); + if (len > 0 && name[len - 1] == '*') { + wildcard = true; + len -= 1; + } for (i = 0; i < NR_TRACE_EVENTS; i++) { + if (wildcard) { + if (!strncmp(trace_list[i].tp_name, name, len)) { + trace_list[i].state = state; + matched = true; + } + continue; + } if (!strcmp(trace_list[i].tp_name, name)) { trace_list[i].state = state; return true; } } - return false; + return matched; } /* Helper function to create a thread with signals blocked. Use glib's diff --git a/trace/stderr.c b/trace/stderr.c index 7107c4a131..0810d6f956 100644 --- a/trace/stderr.c +++ b/trace/stderr.c @@ -15,14 +15,29 @@ void trace_print_events(FILE *stream, fprintf_function stream_printf) bool trace_event_set_state(const char *name, bool state) { unsigned int i; + unsigned int len; + bool wildcard = false; + bool matched = false; + len = strlen(name); + if (len > 0 && name[len - 1] == '*') { + wildcard = true; + len -= 1; + } for (i = 0; i < NR_TRACE_EVENTS; i++) { + if (wildcard) { + if (!strncmp(trace_list[i].tp_name, name, len)) { + trace_list[i].state = state; + matched = true; + } + continue; + } if (!strcmp(trace_list[i].tp_name, name)) { trace_list[i].state = state; return true; } } - return false; + return matched; } bool trace_backend_init(const char *events, const char *file) |