From c85e28b971d527c115ae3e11e9564fb5d40df90c Mon Sep 17 00:00:00 2001
From: Joachim Wiberg <troglobit@gmail.com>
Date: Fri, 9 Apr 2021 18:59:33 +0200
Subject: [PATCH] Yield execution in forked children back to PID 1

 - Speeds up start-up a bit
 - Ensures the child is moved to its cgroup as soon as possible

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 src/exec.c    | 4 ++++
 src/helpers.h | 1 +
 src/service.c | 5 ++++-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/exec.c b/src/exec.c
index c2eee0f4..45f1e3fc 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -389,6 +389,8 @@ pid_t run_getty(char *tty, char *baud, char *term, int noclear, int nowait, stru
 		speed_t speed;
 		int rc = 1;
 
+		sched_yield();
+
 		speed = stty_parse_speed(baud);
 		prepare_tty(tty, speed, "tty", rlimit);
 		if (activate_console(noclear, nowait)) {
@@ -412,6 +414,8 @@ pid_t run_getty2(char *tty, char *cmd, char *args[], int noclear, int nowait, st
 	if (!pid) {
 		int rc = 1;
 
+		sched_yield();
+
 		/* Dunno speed, tell stty() to not mess with it */
 		prepare_tty(tty, B0, "getty", rlimit);
 		if (activate_console(noclear, nowait)) {
diff --git a/src/helpers.h b/src/helpers.h
index 03fac197..54fdd55a 100644
--- a/src/helpers.h
+++ b/src/helpers.h
@@ -26,6 +26,7 @@
 #define FINIT_HELPERS_H_
 
 #include <mntent.h>
+#include <sched.h>		/* sched_yield() */
 #include <stdarg.h>
 #include <sys/resource.h>
 #include <sys/types.h>
diff --git a/src/service.c b/src/service.c
index 4f0320ac..58acd141 100644
--- a/src/service.c
+++ b/src/service.c
@@ -25,7 +25,6 @@
 #include "config.h"		/* Generated by configure script */
 
 #include <ctype.h>		/* isblank() */
-#include <sched.h>		/* sched_yield() */
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/resource.h>
@@ -196,6 +195,8 @@ static int lredirect(svc_t *svc)
 		char *tag  = basename(svc->cmd);
 		char *prio = "daemon.info";
 
+		sched_yield();
+
 		fds = open(ptsname(fd), O_RDONLY);
 		close(fd);
 		if (fds == -1)
@@ -445,6 +446,8 @@ static int service_start(svc_t *svc)
 #endif
 		char *args[MAX_NUM_SVC_ARGS + 1];
 
+		sched_yield();
+
 		/* Set configured limits */
 		for (int i = 0; i < RLIMIT_NLIMITS; i++) {
 			if (setrlimit(i, &svc->rlimit[i]) == -1)