Add rc-analyze

Adds a commandline utility to view various runtime statistics using the event log

Closes: #997

Author: axtloss

man/meson.build

@@ -12,6 +12,7 @@ man3 = [
 man8 = [
   'openrc.8',
   'openrc-run.8',
+  'rc-analyze.8',
   'rc-service.8',
   'rc-status.8',
   'rc-update.8',

man/rc-analyze.8

@@ -0,0 +1,46 @@
+.\" Copyright (c) 2026 The OpenRC Authors.
+.\" See the Authors file at the top-level directory of this distribution and
+.\" https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
+.\"
+.\" This file is part of OpenRC. It is subject to the license terms in
+.\" the LICENSE file found in the top-level directory of this
+.\" distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
+.\" This file may not be copied, modified, propagated, or distributed
+.\"    except according to the terms contained in the LICENSE file.
+.\"
+.Dd April 2, 2026
+.Dt RC-ANALYZE 8 SMM
+.Os OpenRC
+.Sh NAME
+.Nm rc-analyze
+.Nd analyze OpenRC startup performance
+.Sh SYNOPSIS
+.Nm
+.Ar blame | critical-chain | time
+.Sh DESCRIPTION
+The
+.Nm
+utility provides commands to analyze the boot performance of an OpenRC-based
+system.
+.Sh COMMANDS
+The following commands are available:
+.Bl -tag -width ".Fl critical-chain"
+.It Nm blame
+Prints a list of all services that were started, sorted by the time they took
+to start up (longest first). This helps identify the slowest services during
+boot.
+.It Nm critical-chain
+.Op Ar service
+Shows the chain of dependencies that led to the specified
+.Ar service
+starting. If no service is specified, it shows the chain for the last service
+to start in the default runlevel. The output is a tree where each dependency
+is a parent of the service that depends on it. The time at which each service
+became active and the time it took to start are printed.
+.It Nm time
+Prints a summary of the time spent getting to the default runlevel.
+.El
+.Sh SEE ALSO
+.Xr openrc 8 ,
+.Sh AUTHORS
+.An The OpenRC Authors <openrc@lists.gentoo.org>

src/librc/rc-eventlog.c

@@ -17,6 +17,8 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -47,26 +49,15 @@ static const char *rc_service_state_name(RC_SERVICE state)
 }
 
 /*
- * Format the current time as an ISO 8601 timestamp with milliseconds.
- * Returns a dynamically allocated string that must be freed by the caller.
+ * Get the current monotonic time in milliseconds.
  */
-static char *format_timestamp(void)
+static int64_t tm_now(void)
 {
-	time_t now;
-	struct tm *tm;
-	char timebuf[32];
-	char *result;
-	int ms;
+	struct timespec tv;
+	int64_t sec_to_ms = 1000, round_up = 500000, ns_to_ms = 1000000;
 
-	clock_gettime(CLOCK_REALTIME, &ts);
-	tm = localtime(&ts.tv_sec);
-	ms = (int)(ts.tv_nsec / 1000000);
-
-	strftime(timebuf, sizeof(timebuf), "%Y-%m-%dT%H:%M:%S", tm);
-	xasprintf(&result, "%s.%03d%+03ld%02ld", timebuf, ms,
-		tm->tm_gmtoff / 3600, (labs(tm->tm_gmtoff) % 3600) / 60);
-
-	return result;
+	clock_gettime(CLOCK_MONOTONIC, &tv);
+	return (tv.tv_sec * sec_to_ms) + ((tv.tv_nsec + round_up) / ns_to_ms);
 }
 
 /*
@@ -96,7 +87,6 @@ void rc_eventlog_service(const char *service, RC_SERVICE state)
 {
 	int svcfd;
 	int eventsfd;
-	char *timestamp;
 	FILE *fp;
 	const char *state_name;
 
@@ -116,21 +106,16 @@ void rc_eventlog_service(const char *service, RC_SERVICE state)
 
 	service = basename_c(service);
 
-	timestamp = format_timestamp();
-
 	state_name = rc_service_state_name(state);
 
 	fp = do_fopenat(eventsfd, service, O_WRONLY | O_CREAT | O_APPEND);
 	close(eventsfd);
 
-	if (!fp) {
-		free(timestamp);
+	if (!fp)
 		return;
-	}
 
-	fprintf(fp, "%s %s\n", timestamp, state_name);
+	fprintf(fp, "%" PRId64 " %s\n", tm_now(), state_name);
 	fclose(fp);
-	free(timestamp);
 }
 
 /*
@@ -139,7 +124,6 @@ void rc_eventlog_service(const char *service, RC_SERVICE state)
 void rc_eventlog_global(const char *event_type, const char *message)
 {
 	int svcfd;
-	char *timestamp;
 	FILE *fp;
 
 	if (!event_type || !message)
@@ -152,15 +136,10 @@ void rc_eventlog_global(const char *event_type, const char *message)
 	if (rc_eventlog_init() != 0)
 		return;
 
-	timestamp = format_timestamp();
-
 	fp = do_fopenat(svcfd, RC_EVENTLOG_GLOBAL, O_WRONLY | O_CREAT | O_APPEND);
-	if (!fp) {
-		free(timestamp);
+	if (!fp)
 		return;
-	}
 
-	fprintf(fp, "%s %s %s\n", timestamp, event_type, message);
+	fprintf(fp, "%" PRId64 " %s %s\n", tm_now(), event_type, message);
 	fclose(fp);
-	free(timestamp);
 }

src/meson.build

@@ -22,6 +22,7 @@ subdir('openrc-user')
 subdir('pam_openrc')
 subdir('poweroff')
 subdir('rc-abort')
+subdir('rc-analyze')
 subdir('rc-depend')
 subdir('rc-service')
 subdir('rc-sstat')

src/rc-analyze/meson.build

@@ -0,0 +1,7 @@
+libm = cc.find_library('m', required: true)
+
+executable('rc-analyze', 'rc-analyze.c',
+  dependencies: [rc, einfo, shared, libm],
+  include_directories: incdir,
+  install: true,
+  install_dir: bindir)