Add a flush of the current PMC log buffer before displaying the next top.

As the underlying block is 4KB if the PMC throughput is low the measurement
will be reported on the next tick. pmcstat(8) use the modified flush API to
reclaim current buffer before displaying next top.

MFC after:	1 month

2 files changed, 11 insertions, 9 deletions

diff --git a/usr.sbin/pmcstat/pmcstat.c b/usr.sbin/pmcstat/pmcstat.c
index 31ef87770536..5d9db61952db 100644
--- a/usr.sbin/pmcstat/pmcstat.c
+++ b/usr.sbin/pmcstat/pmcstat.c
@@ -552,7 +552,7 @@ main(int argc, char **argv)
 	int hcpu, option, npmc, ncpu;
 	int c, check_driver_stats, current_cpu, current_sampling_count;
 	int do_callchain, do_descendants, do_logproccsw, do_logprocexit;
-	int do_print;
+	int do_print, do_read;
 	size_t dummy;
 	int graphdepth;
 	int pipefd[2], rfd;
@@ -1328,7 +1328,7 @@ main(int argc, char **argv)
 	 * are killed by a SIGINT.
 	 */
 	runstate = PMCSTAT_RUNNING;
-	do_print = 0;
+	do_print = do_read = 0;
 	do {
 		if ((c = kevent(pmcstat_kq, NULL, 0, &kev, 1, NULL)) <= 0) {
 			if (errno != EINTR)
@@ -1351,8 +1351,10 @@ main(int argc, char **argv)
 			    (args.pa_flags & FLAG_DO_TOP)) {
 				if (pmcstat_keypress_log())
 					runstate = pmcstat_close_log();
-			} else
+			} else {
+				do_read = 0;
 				runstate = pmcstat_process_log();
+			}
 			break;
 
 		case EVFILT_SIGNAL:
@@ -1377,9 +1379,6 @@ main(int argc, char **argv)
 				/* Kill the child process if we started it */
 				if (args.pa_flags & FLAG_HAS_COMMANDLINE)
 					pmcstat_kill_process();
-				/* Close the pipe to self, if present. */
-				if (args.pa_flags & FLAG_HAS_PIPE)
-					(void) close(pipefd[READPIPEFD]);
 				runstate = pmcstat_close_log();
 			} else if (kev.ident == SIGWINCH) {
 				if (ioctl(fileno(args.pa_printfile),
@@ -1394,12 +1393,15 @@ main(int argc, char **argv)
 			break;
 
 		case EVFILT_TIMER: /* print out counting PMCs */
+			if ((args.pa_flags & FLAG_DO_TOP) &&
+			     pmc_flush_logfile() != ENOBUFS)
+				do_read = 1;
 			do_print = 1;
 			break;
 
 		}
 
-		if (do_print) {
+		if (do_print && !do_read) {
 			if ((args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) == 0) {
 				pmcstat_print_pmcs();
 				if (runstate == PMCSTAT_FINISHED && /* final newline */
@@ -1420,7 +1422,7 @@ main(int argc, char **argv)
 
 	/* flush any pending log entries */
 	if (args.pa_flags & (FLAG_HAS_OUTPUT_LOGFILE | FLAG_HAS_PIPE))
-		pmc_flush_logfile();
+		pmc_close_logfile();
 
 	pmcstat_cleanup();
 
diff --git a/usr.sbin/pmcstat/pmcstat_log.c b/usr.sbin/pmcstat/pmcstat_log.c
index b7dc956d807b..6d0403f00585 100644
--- a/usr.sbin/pmcstat/pmcstat_log.c
+++ b/usr.sbin/pmcstat/pmcstat_log.c
@@ -1702,7 +1702,7 @@ pmcstat_close_log(void)
 	 * so keep the status to EXITING.
 	 */
 	if (args.pa_logfd != -1) {
-		if (pmc_flush_logfile() < 0)
+		if (pmc_close_logfile() < 0)
 			err(EX_OSERR, "ERROR: logging failed");
 	}