trace: add "-trace enable=..."

Allow enabling events without going through a file, for example:

   qemu-system-x86_64 -trace bdrv_aio_writev -trace bdrv_aio_readv

or with globbing too:

   qemu-system-x86_64 -trace 'bdrv_aio_*'

if an appropriate backend is enabled (simple, stderr, ftrace).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-6-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2016-01-07 16:55:26 +03:00 committed by Stefan Hajnoczi
parent f246b86672
commit 10578a257d
4 changed files with 54 additions and 24 deletions

View File

@ -3544,7 +3544,7 @@ config files on @var{sysconfdir}, but won't make it skip the QEMU-provided confi
files from @var{datadir}.
ETEXI
DEF("trace", HAS_ARG, QEMU_OPTION_trace,
"-trace [events=<file>][,file=<file>]\n"
"-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
" specify tracing options\n",
QEMU_ARCH_ALL)
STEXI
@ -3556,6 +3556,14 @@ HXCOMM HX does not support conditional compilation of text.
Specify tracing options.
@table @option
@item [enable=]@var{pattern}
Immediately enable events matching @var{pattern}.
The file must contain one event name (as listed in the @file{trace-events} file)
per line; globbing patterns are accepted too. This option is only
available if QEMU has been compiled with the @var{simple}, @var{stderr}
or @var{ftrace} tracing backend. To specify multiple events or patterns,
specify the @option{-trace} option multiple times.
@item events=@var{file}
Immediately enable events listed in @var{file}.
The file must contain one event name (as listed in the @file{trace-events} file)

View File

@ -88,6 +88,32 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
return NULL;
}
void trace_enable_events(const char *line_buf)
{
const bool enable = ('-' != line_buf[0]);
const char *line_ptr = enable ? line_buf : line_buf + 1;
if (trace_event_is_pattern(line_ptr)) {
TraceEvent *ev = NULL;
while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
if (trace_event_get_state_static(ev)) {
trace_event_set_state_dynamic(ev, enable);
}
}
} else {
TraceEvent *ev = trace_event_name(line_ptr);
if (ev == NULL) {
error_report("WARNING: trace event '%s' does not exist",
line_ptr);
} else if (!trace_event_get_state_static(ev)) {
error_report("WARNING: trace event '%s' is not traceable",
line_ptr);
} else {
trace_event_set_state_dynamic(ev, enable);
}
}
}
void trace_init_events(const char *fname)
{
Location loc;
@ -114,27 +140,7 @@ void trace_init_events(const char *fname)
if ('#' == line_buf[0]) { /* skip commented lines */
continue;
}
const bool enable = ('-' != line_buf[0]);
char *line_ptr = enable ? line_buf : line_buf + 1;
if (trace_event_is_pattern(line_ptr)) {
TraceEvent *ev = NULL;
while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
if (trace_event_get_state_static(ev)) {
trace_event_set_state_dynamic(ev, enable);
}
}
} else {
TraceEvent *ev = trace_event_name(line_ptr);
if (ev == NULL) {
error_report("WARNING: trace event '%s' does not exist",
line_ptr);
} else if (!trace_event_get_state_static(ev)) {
error_report("WARNING: trace event '%s' is not traceable",
line_ptr);
} else {
trace_event_set_state_dynamic(ev, enable);
}
}
trace_enable_events(line_buf);
}
}
if (fclose(fp) != 0) {

View File

@ -181,6 +181,15 @@ void trace_init_events(const char *file);
*/
void trace_init_file(const char *file);
/**
* trace_enable_events:
* @line_buf: A string with a glob pattern of events to be enabled or,
* if the string starts with '-', disabled.
*
* Enable or disable matching events.
*/
void trace_enable_events(const char *line_buf);
#include "trace/control-internal.h"

11
vl.c
View File

@ -270,9 +270,13 @@ static QemuOptsList qemu_sandbox_opts = {
static QemuOptsList qemu_trace_opts = {
.name = "trace",
.implied_opt_name = "trace",
.implied_opt_name = "enable",
.head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
.desc = {
{
.name = "enable",
.type = QEMU_OPT_STRING,
},
{
.name = "events",
.type = QEMU_OPT_STRING,
@ -3900,10 +3904,13 @@ int main(int argc, char **argv, char **envp)
case QEMU_OPTION_trace:
{
opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
optarg, false);
optarg, true);
if (!opts) {
exit(1);
}
if (qemu_opt_get(opts, "enable")) {
trace_enable_events(qemu_opt_get(opts, "enable"));
}
trace_init_events(qemu_opt_get(opts, "events"));
if (trace_file) {
g_free(trace_file);