Re: [PATCH] Fix failure to resume from initrds.

From: Rafael J. Wysocki
Date: Tue Sep 11 2007 - 06:53:19 EST


On Tuesday, 11 September 2007 05:54, Nigel Cunningham wrote:
> Hi all.
>
> 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.

Hm.

I use a resume from an initrd on a regular basis and it works without the patch
below.

I think we need to investigate what happens in your test case a bit.

> 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.
>
> Signed-off-by: Nigel Cunningham <nigel@xxxxxxxxxxxxxxxxxx>
>
> do_mounts_initrd.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
> diff -ruNp 952-fix-initrd-resume.patch-old/init/do_mounts_initrd.c 952-fix-initrd-resume.patch-new/init/do_mounts_initrd.c
> --- 952-fix-initrd-resume.patch-old/init/do_mounts_initrd.c 2007-09-11 13:43:31.000000000 +1000
> +++ 952-fix-initrd-resume.patch-new/init/do_mounts_initrd.c 2007-09-11 13:19:50.000000000 +1000
> @@ -58,8 +58,10 @@ 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)) {
> yield();
> + try_to_freeze();
> + }
>
> if (!resume_attempted)
> printk(KERN_ERR "Suspend2: No attempt was made to resume from "
>

Greetings,
Rafael
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