Re: 2.6.21-rc7-mm2 suspend bug. [kernel/kthread.c]

From: Andrew Morton
Date: Mon Apr 30 2007 - 03:41:09 EST

On Sun, 29 Apr 2007 22:27:44 +0200 "Rafael J. Wysocki" <rjw@xxxxxxx> wrote:

> On Sunday, 29 April 2007 21:51, Dan Kruchinin wrote:
> > Hi all.
> >
> > There is a problem on my macbook core duo with suspend.
> > after suspending when i'm trying to 'wake up' my notebook, it seems
> > that it works, but i don't see anything at my monitor. So i have to
> > reboot it to continue my work.
> What exactly do you do to suspend?

This is due to _cpu_down() calling kthread_bind() in state TASK_RUNNING.

So I was sent the below, including worrisome changelog.

From: Gautham R Shenoy <ego@xxxxxxxxxx>

We are anyway kthread_stop()ping other per-cpu kernel threads after
move_task_off_dead_cpu(), so we can do it with the stop_machine_run thread
as well.

I just checked with Vatsa if there was any subtle reason why they
had put in the kthread_bind() in cpu.c. Vatsa cannot seem to recollect
any and I can't see any. So let us just remove the kthread_bind.

Signed-off-by: Gautham R Shenoy <ego@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

kernel/cpu.c | 4 ----
1 files changed, 4 deletions(-)

diff -puN kernel/cpu.c~remvoe-kthread_bind-call-from-_cpu_down kernel/cpu.c
--- a/kernel/cpu.c~remvoe-kthread_bind-call-from-_cpu_down
+++ a/kernel/cpu.c
@@ -175,10 +175,6 @@ static int _cpu_down(unsigned int cpu)
/* This actually kills the CPU. */

- /* Move it here so it can run. */
- kthread_bind(p, get_cpu());
- put_cpu();
/* CPU is completely dead: tell everyone. Too late to complain. */
if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD, hcpu) == NOTIFY_BAD)

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at