From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Subject: Re: [PATCH Updated] PM/Freezer: Thaw only kernel threads if freezing of kernel threads fails
Date: Sat, 4 Feb 2012 23:27:09 +0100
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Cc: Tejun Heo <tj@kernel.org>, pavel@ucw.cz, len.brown@intel.com,
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        Nigel Cunningham <nigel@tuxonice.net>
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On Saturday, February 04, 2012, Srivatsa S. Bhat wrote:
> On 02/02/2012 04:29 AM, Srivatsa S. Bhat wrote:
> 
> > 
> > From: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> > Subject: [PATCH] PM/Freezer: Thaw only kernel threads if freezing of kernel threads fails
> > 
> > If freezing of kernel threads fails, we are expected to automatically thaw
> > tasks in the error recovery path. However, at times, we encounter situations
> > in which we would like the automatic error recovery path to thaw only the
> > kernel threads, because we want to be able to do some more cleanup before
> > we thaw userspace. Something like:
> > 
> > error = freeze_kernel_threads();
> > if (error) {
> > 	/* Do some cleanup */
> > 
> > 	/* Only then thaw userspace tasks*/
> > 	thaw_processes();
> > }
> > 
> > An example of such a situation is where we freeze/thaw filesystems during
> > suspend/hibernation. There, if freezing of kernel threads fails, we would
> > like to thaw the frozen filesystems before thawing the userspace tasks.
> > 
> > So, modify freeze_kernel_threads() to thaw only kernel threads in case of
> > freezing failure. And change suspend_freeze_processes() accordingly.
> > (At the same time, let us also get rid of the rather cryptic usage of the
> > conditional operator (:?) in that function.)
> > 
> > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> > Acked-by: Tejun Heo <tj@kernel.org>
> > ---
> 
> 
> Hi Rafael,
> 
> I have reworked the changelog of this patch to indicate that this fixes a
> regression. Here is the updated patch:

Well, I've already fixed that up in my tree, but thanks anyway. :-)

Rafael
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