Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread to kthread worker API

From	Jacob Pan <jacob.jun.pan@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread to kthread worker API
Date	2016-01-12 03:30 +0100
Message-ID	<qPWSC-2Tc-11@gated-at.bofh.it> (permalink)
References	<qwaYa-3sP-5@gated-at.bofh.it> <qwaYc-3sP-41@gated-at.bofh.it> <qOoSZ-4ij-3@gated-at.bofh.it> <qOIoH-UX-15@gated-at.bofh.it>
Organization	OTC

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On Fri, 8 Jan 2016 17:49:31 +0100
Petr Mladek <pmladek@suse.com> wrote:

> Is the __preempt_schedule() a problem? It allows to switch the process
> when needed. I thought that it was safe because try_to_freeze() might
> have slept as well.
> 
not a problem. i originally thought queue_kthread_work() may add
delay but it doesn't since there is no other work on this kthread.
> 
> > - vulnerable to future changes of queuing work  
> 
> The question is if it is safe to sleep, freeze, or even migrate
> the system between the works. It looks like because of the
> try_to_freeze() and schedule_interrupt() calls in the original code.
> 
> BTW: I wonder if the original code correctly handle freezing after
> the schedule_timeout(). It does not call try_to_freeze()
> there and the forced idle states might block freezing.
> I think that the small overhead of kthread works is worth
> solving such bugs. It makes it easier to maintain these
> sleeping states.
it is in a while loop, so try_to_freeze() gets called. Am I missing
something?

Thanks,

Jacob

Thread

Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Jacob Pan <jacob.jun.pan@linux.intel.com> - 2016-01-07 21:00 +0100
  Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Petr Mladek <pmladek@suse.com> - 2016-01-08 17:50 +0100
    Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Jacob Pan <jacob.jun.pan@linux.intel.com> - 2016-01-12 03:30 +0100
      Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Petr Mladek <pmladek@suse.com> - 2016-01-12 11:20 +0100
        Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Jacob Pan <jacob.jun.pan@linux.intel.com> - 2016-01-12 17:30 +0100
          Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Petr Mladek <pmladek@suse.com> - 2016-01-13 11:20 +0100
            Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Jacob Pan <jacob.jun.pan@linux.intel.com> - 2016-01-13 19:00 +0100
              Re: [PATCH v3 22/22] thermal/intel_powerclamp: Convert the kthread  to kthread worker API Petr Mladek <pmladek@suse.com> - 2016-01-14 16:40 +0100

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