Messages in this thread | | | Date | Tue, 12 Jul 2016 14:52:43 +0200 | From | Petr Mladek <> | Subject | Re: [Query] Preemption (hogging) of the work handler |
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On Tue 2016-07-12 18:38:05, Sergey Senozhatsky wrote: > Hello, > > On (07/11/16 15:35), Viresh Kumar wrote: > [..] > > Sometimes, the platform doesn't come back after suspend. I have tried > > enabling no-console-suspend and the last line it prints is: > > > > Disabling non-boot CPUs
I guess that the printk() kthread is not longer scheduled when there is only one CPU left.
> > And nothing after that at all. We have to forcefully reboot the phone > > after that. Moving the prints to they synchronous way (using > > echo 1 > /sys/module/printk/parameters/synchronous), fixes that issue. > > hm... I'll take a look.
We might try to explicitly flush the consoles in suspend_console(). But I am not sure if we always want to do so because it might take a while. Also it need not help if someone already owns the console_sem. Note the console_unlock() calls the cond_resched() when in safe context.
Well, we might do the best effort when no_console_suspend is enabled.
Best Regards, Petr
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