Fix failure to resume from initrds

[Please consider as 2.6.23 material]
---
From: Nigel Cunningham <[email protected]>

Commit 831441862956fffa17b9801db37e6ea1650b0f69 (Freezer: make kernel threads nonfreezable by default) breaks freezing when attempting to resume from an initrd, because the init (which is freezeable) spins while waiting for another thread to run /linuxrc, but doesn't check whether it has been told to enter the refrigerator. The original patch replaced a call to try_to_freeze() with a call to yield(). I believe a simple reversion is wrong because
if !CONFIG_PM_SLEEP, try_to_freeze() is a noop. It should still yield.

---
 init/do_mounts_initrd.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.23-rc6/init/do_mounts_initrd.c
===================================================================
@@ -57,8 +57,10 @@ static void __init handle_initrd(void)
 
 	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 	if (pid > 0)
-		while (pid != sys_wait4(-1, NULL, 0, NULL))
+		while (pid != sys_wait4(-1, NULL, 0, NULL)) {
+			try_to_freeze();
 			yield();
+		}
 
 	/* move initrd to rootfs' /old */
 	sys_fchdir(old_fd);

Hi!

ACK.
Pavel

(english) http://www.livejournal.com/~pavelmachek
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