[sysvinit-devel] [PATCH] Increase sleep granularity at shutdown to 10 milliseconds.

[Serge Belyshev]

Due to do_sleep one second granularity, children killing logic
always causes one second delay at shutdown, even if all processes
successfully terminate long before that.

Fixed thus by replacing do_sleep with do_msleep and waiting for
children to terminate every 10 ms.
---
 src/init.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/init.c b/src/init.c
index 4369beb..3b4b4af 100644
--- a/src/init.c
+++ b/src/init.c
@@ -229,18 +229,18 @@ char *extra_env[NR_EXTRA_ENV];
 
 
 /*
- *     Sleep a number of seconds.
+ *     Sleep a number of milliseconds.
  *
  *     This only works correctly because the linux select updates
  *     the elapsed time in the struct timeval passed to select!
  */
 static
-void do_sleep(int sec)
+void do_msleep(int msec)
 {
        struct timeval tv;
 
-       tv.tv_sec = sec;
-       tv.tv_usec = 0;
+       tv.tv_sec = msec / 1000;
+       tv.tv_usec = (msec % 1000) * 1000;
 
        while(select(0, NULL, NULL, NULL, &tv) < 0 && errno == EINTR)
                ;
@@ -257,7 +257,7 @@ void *imalloc(size_t size)
 
        while ((m = malloc(size)) == NULL) {
                initlog(L_VB, "out of memory");
-               do_sleep(5);
+               do_msleep(5000);
        }
        memset(m, 0, size);
        return m;
@@ -723,7 +723,7 @@ void coredump(void)
        sigdelset(&mask, SIGSEGV);
        sigprocmask(SIG_SETMASK, &mask, NULL);
 
-       do_sleep(5);
+       do_msleep(5000);
        exit(0);
 }
 
@@ -749,7 +749,7 @@ void segv_handler(int sig, struct sigcontext ctx)
        initlog(L_VB, "PANIC: segmentation violation at %p%s! "
                  "sleeping for 30 seconds.", (void *)ctx.eip, p);
        coredump();
-       do_sleep(30);
+       do_msleep(30000);
        errno = saved_errno;
 }
 #else
@@ -764,7 +764,7 @@ void segv_handler(int sig)
        initlog(L_VB,
                "PANIC: segmentation violation! sleeping for 30 seconds.");
        coredump();
-       do_sleep(30);
+       do_msleep(30000);
        errno = saved_errno;
 }
 #endif
@@ -978,7 +978,7 @@ char **init_buildenv(int child)
 
        while ((e = (char**)calloc(n, sizeof(char *))) == NULL) {
                initlog(L_VB, "out of memory");
-               do_sleep(5);
+               do_msleep(5000);
        }
 
        for (n = 0; environ[n]; n++)
@@ -1304,7 +1304,7 @@ pid_t spawn(CHILD *ch, int *res)
 
        if (pid == -1) {
                initlog(L_VB, "cannot fork, retry..");
-               do_sleep(5);
+               do_msleep(5000);
                continue;
        }
        return(pid);
@@ -1712,13 +1712,13 @@ void read_inittab(void)
        
     }
     /*
-     * See if we have to wait 5 seconds
+     * See if we have to wait sleep_time seconds
      */
     if (foundOne && round == 0) {
        /*
-        *      Yup, but check every second if we still have children.
+        *      Yup, but check every 10 milliseconds if we still have children.
         */
-       for(f = 0; f < sleep_time; f++) {
+       for(f = 0; f < 100 * sleep_time; f++) {
                for(ch = family; ch; ch = ch->next) {
                        if (!(ch->flags & KILLME)) continue;
                        if ((ch->flags & RUNNING) && !(ch->flags & ZOMBIE))
@@ -1732,7 +1732,7 @@ void read_inittab(void)
                        foundOne = 0; /* Skip the sleep below. */
                        break;
                }
-               do_sleep(1);
+               do_msleep(10);
        }
     }
   }
@@ -1740,7 +1740,7 @@ void read_inittab(void)
   /*
    *   Now give all processes the chance to die and collect exit statuses.
    */
-  if (foundOne) do_sleep(1);
+  if (foundOne) do_msleep(10);
   for(ch = family; ch; ch = ch->next)
        if (ch->flags & KILLME) {
                if (!(ch->flags & ZOMBIE))
-- 
2.20.1