[PATCH v3 3/5] trace-cmd stop, reset, restart: Add -a for all instances

From: Howard Cochran
Date: Wed Apr 22 2015 - 00:57:40 EST

As for extract, -a means all instances except the top one.
Use -t to get the top one too.

Signed-off-by: Howard Cochran <hcochran@xxxxxxxxxxxxxxxx>
---
Documentation/trace-cmd-reset.1.txt | 57 +++++++++++++++++++++++++++++++++----
Documentation/trace-cmd-stop.1.txt | 13 ++++++---
trace-record.c | 57 ++++++++++++++++++++++++++++++-------
trace-usage.c | 21 ++++++++------
4 files changed, 119 insertions(+), 29 deletions(-)

diff --git a/Documentation/trace-cmd-reset.1.txt b/Documentation/trace-cmd-reset.1.txt
index 06a60af..bff4530 100644
--- a/Documentation/trace-cmd-reset.1.txt
+++ b/Documentation/trace-cmd-reset.1.txt
@@ -22,6 +22,9 @@ the data in the ring buffer, and the options that were used are all lost.

OPTIONS
-------
+Please note that the order that options are specified on the command line is
+significant. See EXAMPLES.
+
*-b* 'buffer_size'::
When the kernel boots, the Ftrace ring buffer is of a minimal size (3
pages per CPU). The first time the tracer is used, the ring buffer size
@@ -32,6 +35,17 @@ OPTIONS

trace-cmd reset -b 1

+ The buffer instance affected is the one (or ones) specified by the most
+ recently preceding *-B*, *-t*, or *-a* option:
+
+ When used after *-B*, resizes the buffer instance that precedes it on
+ the command line.
+
+ When used after *-a*, resizes all buffer instances except the top one.
+
+ When used after *-t* or before any *-B* or *-a*, resizes the top
+ instance.
+
*-B* 'buffer-name'::
If the kernel supports multiple buffers, this will reset the trace for
only the given buffer. It does not affect any other buffer. This may be
@@ -39,15 +53,46 @@ OPTIONS
will not be reset if this option is given (unless the *-t* option is
also supplied).

+*-a*::
+ Reset the trace for all existing buffer instances. When this option
+ is used, the top level instance will not be reset unless *-t* is given.
+
*-d*::
- Delete the previously specified buffer instance that was specified by
- the *-B* option. It is invalid to use with *-t* as the top level instance
- can not be deleted.
+ This option deletes the instance buffer(s) specified by the most recently
+ preceding *-B* or *-a* option. Because the top-level instance buffer
+ cannot be deleted, it is invalid to use this immediatly following *-t* or
+ prior to any *-B* or *-a* option on the command line.

*-t*::
- Resets the top level instance buffer. Without the *-B* option this is the
- same as the default. But if *-B* is used, this is required if the top
- level instance buffer should also be reset.
+ Resets the top level instance buffer. Without the *-B* or *-a* option
+ this is the same as the default. But if *-B* or *-a* is used, this is
+ required if the top level instance buffer should also be reset.
+
+EXAMPLES
+--------
+
+Reset tracing for instance-one and set its per-cpu buffer size to 4096kb.
+Also deletes instance-two. The top level instance and any other instances
+remain unaffected:
+
+ trace-cmd reset -B instance-one -b 4096 -B instance-two -d
+
+Delete all instance buffers. Top level instance remains unaffected:
+
+ trace-cmd reset -a -d
+
+Delete all instance buffers and also reset the top instance:
+
+ trace-cmd reset -t -a -d
+
+Invalid. This command implies an attempt to delete the top instance:
+
+ trace-cmd reset -a -t -d
+
+Reset the top instance and set its per-cpu buffer size to 1024kb. If any
+instance buffers exist, they will be unaffected:
+
+ trace-cmd reset -b 1024


SEE ALSO
diff --git a/Documentation/trace-cmd-stop.1.txt b/Documentation/trace-cmd-stop.1.txt
index c3f8b33..9d4093e 100644
--- a/Documentation/trace-cmd-stop.1.txt
+++ b/Documentation/trace-cmd-stop.1.txt
@@ -30,12 +30,17 @@ OPTIONS
*-B* 'buffer-name'::
If the kernel supports multiple buffers, this will stop the trace for
only the given buffer. It does not affect any other buffer. This may be
- used multiple times to specify different buffers.
+ used multiple times to specify different buffers. When this option is
+ used, the top level instance will not be stopped unless *-t* is given.
+
+*-a*::
+ Stop the trace for all existing buffer instances. When this option
+ is used, the top level instance will not be stopped unless *-t* is given.

*-t*::
- Stops the top level instance buffer. Without the *-B* option this is the
- same as the default. But if *-B* is used, this is required if the top
- level instance buffer should also be stopped.
+ Stops the top level instance buffer. Without the *-B* or *-a* option this
+ is the same as the default. But if *-B* or *-a* is used, this is
+ required if the top level instance buffer should also be stopped.

SEE ALSO
--------
diff --git a/trace-record.c b/trace-record.c
index 4a78fff..7c6b7e9 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -311,7 +311,7 @@ struct buffer_instance *create_instance(const char *name)
*
* Returns whether the operation succeeded
*/
-int add_all_instances(const char *tracing_dir)
+int __add_all_instances(const char *tracing_dir)
{
struct dirent *dent;
char *instances_dir;
@@ -3844,7 +3844,7 @@ void trace_record (int argc, char **argv)
for (;;) {
int c;

- c = getopt(argc-1, argv+1, "tB:");
+ c = getopt(argc-1, argv+1, "hatB:");
if (c == -1)
break;
switch (c) {
@@ -3855,6 +3855,9 @@ void trace_record (int argc, char **argv)
instance = create_instance(optarg);
add_instance(instance);
break;
+ case 'a':
+ add_all_instances();
+ break;
case 't':
/* Force to use top instance */
topt = 1;
@@ -3872,7 +3875,7 @@ void trace_record (int argc, char **argv)
for (;;) {
int c;

- c = getopt(argc-1, argv+1, "tB:");
+ c = getopt(argc-1, argv+1, "hatB:");
if (c == -1)
break;
switch (c) {
@@ -3883,6 +3886,9 @@ void trace_record (int argc, char **argv)
instance = create_instance(optarg);
add_instance(instance);
break;
+ case 'a':
+ add_all_instances();
+ break;
case 't':
/* Force to use top instance */
topt = 1;
@@ -3897,16 +3903,33 @@ void trace_record (int argc, char **argv)
enable_tracing();
exit(0);
} else if (strcmp(argv[1], "reset") == 0) {
+ /* if last arg is -a, then -b and -d apply to all instances */
+ int last_specified_all = 0;
+ struct buffer_instance *inst; /* iterator */
+
+ while ((c = getopt(argc-1, argv+1, "hab:B:td")) >= 0) {

- while ((c = getopt(argc-1, argv+1, "b:B:td")) >= 0) {
switch (c) {
+ case 'h':
+ usage(argv);
+ break;
case 'b':
- instance->buffer_size = atoi(optarg);
+ {
+ int size = atoi(optarg);
/* Min buffer size is 1 */
- if (strcmp(optarg, "0") == 0)
- instance->buffer_size = 1;
+ if (size <= 1)
+ size = 1;
+ if (last_specified_all) {
+ for_each_instance(inst) {
+ inst->buffer_size = size;
+ }
+ } else {
+ instance->buffer_size = size;
+ }
break;
+ }
case 'B':
+ last_specified_all = 0;
instance = create_instance(optarg);
add_instance(instance);
/* -d will remove keep */
@@ -3914,13 +3937,27 @@ void trace_record (int argc, char **argv)
break;
case 't':
/* Force to use top instance */
+ last_specified_all = 0;
topt = 1;
instance = &top_instance;
break;
+ case 'a':
+ last_specified_all = 1;
+ add_all_instances();
+ for_each_instance(instance) {
+ instance->keep = 1;
+ }
+ break;
case 'd':
- if (is_top_instance(instance))
- die("Can not delete top level buffer");
- instance->keep = 0;
+ if (last_specified_all) {
+ for_each_instance(inst) {
+ inst->keep = 0;
+ }
+ } else {
+ if (is_top_instance(instance))
+ die("Can not delete top level buffer");
+ instance->keep = 0;
+ }
break;
}
}
diff --git a/trace-usage.c b/trace-usage.c
index 39de386..c56661b 100644
--- a/trace-usage.c
+++ b/trace-usage.c
@@ -72,20 +72,22 @@ static struct usage_help usage_help[] = {
{
"stop",
"stop the kernel from recording trace data",
- " %s stop [-B buf [-B buf]..] [-t]\n"
+ " %s stop [-B buf [-B buf]..] [-a] [-t]\n"
" Stops the tracer from recording more data.\n"
" Used in conjunction with start\n"
- " -B stop a given buffer (more than one may be specified)\n "
- " -t stop the top level buffer (needed if -B is specified)\n"
+ " -B stop a given buffer (more than one may be specified)\n"
+ " -a stop all buffers (except top one)\n"
+ " -t stop the top level buffer (useful with -B or -a)\n"
},
{
"restart",
"restart the kernel trace data recording",
- " %s restart [-B buf [-B buf]..] [-t]\n"
+ " %s restart [-B buf [-B buf]..] [-a] [-t]\n"
" Restarts recording after a trace-cmd stop.\n"
" Used in conjunction with stop\n"
- " -B restart a given buffer (more than one may be specified)\n "
- " -t restart the top level buffer (needed if -B is specified)\n"
+ " -B restart a given buffer (more than one may be specified)\n"
+ " -a restart all buffers (except top one)\n"
+ " -t restart the top level buffer (useful with -B or -a)\n"
},
{
"show",
@@ -114,13 +116,14 @@ static struct usage_help usage_help[] = {
{
"reset",
"disable all kernel tracing and clear the trace buffers",
- " %s reset [-b size][-B buf][-d][-t]\n"
+ " %s reset [-b size][-B buf][-a][-d][-t]\n"
" Disables the tracer (may reset trace file)\n"
" Used in conjunction with start\n"
" -b change the kernel buffer size (in kilobytes per CPU)\n"
- " -B reset the given buffer instance (top instance ignored)\n"
" -d delete the previous specified instance\n"
- " -t still reset the top instance if -B option is given\n"
+ " -B reset the given buffer instance (may specify multiple -B)\n"
+ " -a reset all instances (except top one)\n"
+ " -t reset the top level instance (useful with -B or -a)\n"
},
{
"report",
--
1.9.1

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