lkml.org 
[lkml]   [2017]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 1/2] livepatch: send a fake signal to all blocking tasks
On 11/01, Petr Mladek wrote:
>
> On Tue 2017-10-31 12:48:52, Miroslav Benes wrote:
> > + if (task->flags & PF_KTHREAD) {
> > + /*
> > + * Wake up a kthread which still has not been migrated.
> > + */
> > + wake_up_process(task);
>
> I have just noticed that freezer used wake_up_state(p, TASK_INTERRUPTIBLE);
> IMHO, we should do so as well.

I won't argue, but...

> wake_up_process() wakes also tasks in TASK_UNINTERRUPTIBLE state.
> These might not be ready for an unexpected wakeup. For example,
> see concat_dev_erase() in drivers/mtd/mtdcontact.c.

I'd say that concat_dev_erase() should be fixed, any code should be ready
for spurious wakeup.

Note also that wake_up_state(TASK_INTERRUPTIBLE) won't wakeup the TASK_IDLE
kthreads, and most of the kthreads which use TASK_INTERRUPTIBLE should use
TASK_IDLE today, because in most cases TASK_INTERRUPTIBLE was used to not
contribute to loadavg.

Oleg.

\
 
 \ /
  Last update: 2017-11-01 17:44    [W:0.124 / U:0.184 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site