Add a command line argument (-l) to end event collection after some

number of seconds.  The number of seconds may be a fraction.

Submitted by:	Julien Charbon <jcharbon@versign.com>
MFC after:	2 weeks
Relnotes:	yes

3 files changed, 51 insertions, 3 deletions

diff --git a/usr.sbin/pmcstat/pmcstat.8 b/usr.sbin/pmcstat/pmcstat.8
index 97a2f62..66d2960 100644
--- a/usr.sbin/pmcstat/pmcstat.8
+++ b/usr.sbin/pmcstat/pmcstat.8
@@ -52,6 +52,7 @@
 .Op Fl f Ar pluginopt
 .Op Fl g
 .Op Fl k Ar kerneldir
+.Op Fl l Ar secs
 .Op Fl m Ar pathname
 .Op Fl n Ar rate
 .Op Fl o Ar outputfile
@@ -274,6 +275,13 @@ This directory specifies where
 should look for the kernel and its modules.
 The default is
 .Pa /boot/kernel .
+.It Fl l Ar secs
+Set system-wide performance measurement duration for
+.Ar secs
+seconds.
+The argument
+.Ar secs
+may be a fractional value.
 .It Fl m Ar pathname
 Print the sampled PCs with the name, the start and ending addresses
 of the function within they live.
diff --git a/usr.sbin/pmcstat/pmcstat.c b/usr.sbin/pmcstat/pmcstat.c
index ae93b93..a045706 100644
--- a/usr.sbin/pmcstat/pmcstat.c
+++ b/usr.sbin/pmcstat/pmcstat.c
@@ -509,6 +509,7 @@ pmcstat_show_usage(void)
 	    "\t -f spec\t pass \"spec\" to as plugin option\n"
 	    "\t -g\t\t produce gprof(1) compatible profiles\n"
 	    "\t -k dir\t\t set the path to the kernel\n"
+	    "\t -l secs\t set duration time\n"
 	    "\t -m file\t print sampled PCs to \"file\"\n"
 	    "\t -n rate\t set sampling rate\n"
 	    "\t -o file\t send print output to \"file\"\n"
@@ -551,6 +552,7 @@ main(int argc, char **argv)
 {
 	cpuset_t cpumask;
 	double interval;
+	double duration;
 	int hcpu, option, npmc, ncpu;
 	int c, check_driver_stats, current_sampling_count;
 	int do_callchain, do_descendants, do_logproccsw, do_logprocexit;
@@ -600,6 +602,7 @@ main(int argc, char **argv)
 	args.pa_toptty		= 0;
 	args.pa_topcolor	= 0;
 	args.pa_mergepmc	= 0;
+	args.pa_duration	= 0.0;
 	STAILQ_INIT(&args.pa_events);
 	SLIST_INIT(&args.pa_targets);
 	bzero(&ds_start, sizeof(ds_start));
@@ -618,7 +621,7 @@ main(int argc, char **argv)
 		CPU_SET(hcpu, &cpumask);
 
 	while ((option = getopt(argc, argv,
-	    "CD:EF:G:M:NO:P:R:S:TWa:c:df:gk:m:n:o:p:qr:s:t:vw:z:")) != -1)
+	    "CD:EF:G:M:NO:P:R:S:TWa:c:df:gk:l:m:n:o:p:qr:s:t:vw:z:")) != -1)
 		switch (option) {
 		case 'a':	/* Annotate + callgraph */
 			args.pa_flags |= FLAG_DO_ANNOTATE;
@@ -692,6 +695,15 @@ main(int argc, char **argv)
 			args.pa_flags    |= FLAG_HAS_KERNELPATH;
 			break;
 
+		case 'l':	/* time duration in seconds */
+			duration = strtod(optarg, &end);
+			if (*end != '\0' || duration <= 0)
+				errx(EX_USAGE, "ERROR: Illegal duration time "
+				    "value \"%s\".", optarg);
+			args.pa_flags |= FLAG_HAS_DURATION;
+			args.pa_duration = duration;
+			break;
+
 		case 'm':
 			args.pa_flags |= FLAG_DO_ANNOTATE;
 			args.pa_plugin = PMCSTAT_PL_ANNOTATE;
@@ -922,6 +934,12 @@ main(int argc, char **argv)
 		errx(EX_USAGE,
 		    "ERROR: options -O and -R are mutually exclusive.");
 
+	/* disallow -T and -l together */
+	if ((args.pa_flags & FLAG_HAS_DURATION) &&
+	    (args.pa_flags & FLAG_DO_TOP))
+		errx(EX_USAGE, "ERROR: options -T and -l are mutually "
+		    "exclusive.");
+
 	/* -m option is allowed with -R only. */
 	if (args.pa_flags & FLAG_DO_ANNOTATE && args.pa_inputpath == NULL)
 		errx(EX_USAGE, "ERROR: option %s requires an input file",
@@ -1279,6 +1297,20 @@ main(int argc, char **argv)
 			    "ERROR: Cannot register kevent for timer");
 	}
 
+	/*
+	 * Setup a duration timer if we have sampling mode PMCs and
+	 * a duration time is set
+	 */
+	if ((args.pa_flags & FLAG_HAS_SAMPLING_PMCS) &&
+	    (args.pa_flags & FLAG_HAS_DURATION)) {
+		EV_SET(&kev, 0, EVFILT_TIMER, EV_ADD, 0,
+		    args.pa_duration * 1000, NULL);
+
+		if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
+			err(EX_OSERR, "ERROR: Cannot register kevent for "
+			    "time duration");
+	}
+
 	/* attach PMCs to the target process, starting it if specified */
 	if (args.pa_flags & FLAG_HAS_COMMANDLINE)
 		pmcstat_create_process();
@@ -1355,7 +1387,7 @@ main(int argc, char **argv)
 
 	/*
 	 * loop till either the target process (if any) exits, or we
-	 * are killed by a SIGINT.
+	 * are killed by a SIGINT or we reached the time duration.
 	 */
 	runstate = PMCSTAT_RUNNING;
 	do_print = do_read = 0;
@@ -1422,7 +1454,13 @@ main(int argc, char **argv)
 
 			break;
 
-		case EVFILT_TIMER: /* print out counting PMCs */
+		case EVFILT_TIMER:
+			/* time duration reached, exit */
+			if (args.pa_flags & FLAG_HAS_DURATION) {
+				runstate = PMCSTAT_FINISHED;
+				break;
+			}
+			/* print out counting PMCs */
 			if ((args.pa_flags & FLAG_DO_TOP) &&
 			     pmc_flush_logfile() == 0)
 				do_read = 1;
diff --git a/usr.sbin/pmcstat/pmcstat.h b/usr.sbin/pmcstat/pmcstat.h
index c8ec14d..a3738c1 100644
--- a/usr.sbin/pmcstat/pmcstat.h
+++ b/usr.sbin/pmcstat/pmcstat.h
@@ -54,6 +54,7 @@
 #define	FLAG_DO_TOP			0x00010000	/* -T */
 #define	FLAG_DO_ANALYSIS		0x00020000	/* -g or -G or -m or -T */
 #define	FLAGS_HAS_CPUMASK		0x00040000	/* -c */
+#define	FLAG_HAS_DURATION		0x00080000	/* -l secs */
 
 #define	DEFAULT_SAMPLE_COUNT		65536
 #define	DEFAULT_WAIT_INTERVAL		5.0
@@ -149,6 +150,7 @@ struct pmcstat_args {
 	int	pa_toptty;		/* output to tty or file */
 	int	pa_topcolor;		/* terminal support color */
 	int	pa_mergepmc;		/* merge PMC with same name */
+	double	pa_duration;		/* time duration */
 	int	pa_argc;
 	char	**pa_argv;
 	STAILQ_HEAD(, pmcstat_ev) pa_events;