Messages in this thread | | | From | Uli Luckas <> | Subject | Re: [RFC][PATCH -mm] PM: Prevent frozen user mode helpers from failing the freezing of tasks | Date | Wed, 20 Jun 2007 11:14:35 +0200 |
| |
On Monday, 18. June 2007, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@sisk.pl> > > At present, if a user mode helper is running while > usermodehelper_pm_callback() is executed, the helper may be frozen and the > completion in > call_usermodehelper_exec() won't be completed until user space processes > are thawed. As a result, the freezing of kernel threads may fail, which is > not desirable. > > Prevent this from happening by introducing a counter of running user mode > helpers and allowing usermodehelper_pm_callback() to succeed for > action = PM_HIBERNATION_PREPARE or action = PM_SUSPEND_PREPARE only if > there are no helpers running. [Namely, usermodehelper_pm_callback() waits > for at most RUNNING_HELPERS_TIMEOUT for the number of running helpers to > become zero and fails if that doesn't happen.] > > Special thanks to Uli Luckas <u.luckas@road.de> for reviewing the previous > versions of this patch and for very useful comments. >
Acked-by: Uli Luckas <u.luckas@road.de>
Regards, Uli
--
------- ROAD ...the handyPC Company - - - ) ) )
Uli Luckas Software Development
ROAD GmbH Bennigsenstr. 14 | 12159 Berlin | Germany fon: +49 (30) 230069 - 64 | fax: +49 (30) 230069 - 69 url: www.road.de
Amtsgericht Charlottenburg: HRB 96688 B Managing directors: Hans-Peter Constien, Hubertus von Streit - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |