Commit 10578a25 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Stefan Hajnoczi
Browse files

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: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-6-git-send-email-den@openvz.org
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent f246b866

qemu-options.hx

+9 −1
Original line number Diff line number Diff line
@@ -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)

trace/control.c

+27 −21
Original line number Diff line number Diff line
@@ -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) {

trace/control.h

+9 −0
Original line number Diff line number Diff line
@@ -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"

vl.c

+9 −2
Original line number Diff line number Diff line
@@ -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);