Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH -mm 2/2] PM: Disable usermode helper before hibernation and suspend | Date | Fri, 15 Jun 2007 23:36:45 +0200 |
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On Friday, 15 June 2007 15:08, Uli Luckas wrote: > On Monday, 4. June 2007, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rjw@sisk.pl> > > > > Use a hibernation and suspend notifier to disable the user mode helper > > before a hibernation/suspend and enable it after the operation. > > > Hi Rafael, > I have a couple of questions, regarding this patch ... > > - if (!khelper_wq) > > + if (!khelper_wq || usermodehelper_disabled) > > return -EBUSY; > 1) how about not returning -EBUSY here, if (wait == UMH_NO_WAIT)?
Yes, this would make sense.
> 2) how does your patch prevent wait_for_completion(&done) to hang during > freezing if usermodehelper_pm_callback is called _after_ the above check?
It doesn't. Once the helper is running, we can't distinguish it from any other user land process.
Still, it narrows the window quite a bit.
Greetings, Rafael
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