linux-kernel - [PATCH v7 09/13] perf stat: implement control commands handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <67630441-400e-0045-c4f9-ef8e486a6559@linux.intel.com>
Date:   Wed, 3 Jun 2020 18:59:20 +0300
From:   Alexey Budankov <alexey.budankov@...ux.intel.com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Jiri Olsa <jolsa@...hat.com>, Namhyung Kim <namhyung@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Andi Kleen <ak@...ux.intel.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: [PATCH v7 09/13] perf stat: implement control commands handling


Implement handling of 'enable' and 'disable' control commands
coming from control file descriptor. process_evlist() function
checks for events on static fds and makes required operations.
If poll event splits initiated timeout interval then the reminder
is calculated and still waited in the following poll() syscall.

Signed-off-by: Alexey Budankov <alexey.budankov@...ux.intel.com>
---
 tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
 1 file changed, 50 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f88d5ee55022..cc56d71a3ed5 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
 	return print_interval(interval, times);
 }
 
+static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
+{
+	bool stop = false;
+	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
+
+	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
+		switch (cmd) {
+		case EVLIST_CTL_CMD_ENABLE:
+			pr_info(EVLIST_ENABLED_MSG);
+			stop = print_interval(interval, times);
+			break;
+		case EVLIST_CTL_CMD_DISABLE:
+			stop = print_interval(interval, times);
+			pr_info(EVLIST_DISABLED_MSG);
+			break;
+		case EVLIST_CTL_CMD_ACK:
+		case EVLIST_CTL_CMD_UNSUPPORTED:
+		default:
+			break;
+		}
+	}
+
+	return stop;
+}
+
 static void enable_counters(void)
 {
 	if (stat_config.initial_delay < 0) {
@@ -567,10 +592,21 @@ static bool is_target_alive(struct target *_target,
 	return false;
 }
 
-static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts)
+static int dispatch_events(bool forks, int timeout, int interval, int *times)
 {
 	bool stop = false;
 	int child = 0, status = 0;
+	int time_to_sleep, sleep_time;
+	struct timespec time_start, time_stop, time_diff;
+
+	if (interval)
+		sleep_time = interval;
+	else if (timeout)
+		sleep_time = timeout;
+	else
+		sleep_time = 1000;
+
+	time_to_sleep = sleep_time;
 
 	while (1) {
 		if (forks)
@@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
 		if (done || stop || child)
 			break;
 
-		nanosleep(ts, NULL);
-		stop = process_timeout(timeout, interval, times);
+		clock_gettime(CLOCK_MONOTONIC, &time_start);
+		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
+			stop = process_timeout(timeout, interval, times);
+			time_to_sleep = sleep_time;
+		} else { /* fd revent */
+			stop = process_evlist(evsel_list, interval, times);
+			clock_gettime(CLOCK_MONOTONIC, &time_stop);
+			diff_timespec(&time_diff, &time_stop, &time_start);
+			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
+					time_diff.tv_nsec / NSEC_PER_MSEC;
+		}
 	}
 
 	return status;
@@ -651,7 +696,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	char msg[BUFSIZ];
 	unsigned long long t0, t1;
 	struct evsel *counter;
-	struct timespec ts;
 	size_t l;
 	int status = 0;
 	const bool forks = (argc > 0);
@@ -660,17 +704,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	int i, cpu;
 	bool second_pass = false;
 
-	if (interval) {
-		ts.tv_sec  = interval / USEC_PER_MSEC;
-		ts.tv_nsec = (interval % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else if (timeout) {
-		ts.tv_sec  = timeout / USEC_PER_MSEC;
-		ts.tv_nsec = (timeout % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else {
-		ts.tv_sec  = 1;
-		ts.tv_nsec = 0;
-	}
-
 	if (forks) {
 		if (perf_evlist__prepare_workload(evsel_list, &target, argv, is_pipe,
 						  workload_exec_failed_signal) < 0) {
@@ -828,7 +861,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 		enable_counters();
 
 		if (interval || timeout)
-			status = dispatch_events(forks, timeout, interval, &times, &ts);
+			status = dispatch_events(forks, timeout, interval, &times);
 		if (child_pid != -1) {
 			if (timeout)
 				kill(child_pid, SIGTERM);
@@ -845,7 +878,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		dispatch_events(forks, timeout, interval, &times, &ts);
+		dispatch_events(forks, timeout, interval, &times);
 	}
 
 	disable_counters();
-- 
2.24.1