Messages in this thread | | | Date | Mon, 04 Jan 2010 13:46:16 +0100 | From | Daniel Borkmann <> | Subject | Re: [suspend/resume] Re: userspace notification from module |
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Rafael J. Wysocki wrote: > On Monday 04 January 2010, Bartłomiej Zimoń wrote: >> And what do You think about sending extra signals to processes? > > I don't see a problem with this in principle, although I don't think signals > are very suitable for this particular purpose, because you need two-way > communication between the power manager and the processes it's going to > notify (because it has to wait for the processes to finish their preparations > and to tell it that they are ready).
Again, just to abandon some thoughts... do you really need that "two-way communication"? I mean if the kernel delivers that specific signal to the process/task_struct [do_signal():handle_signal()] it has to save the original execution context that will later on be restored after the non-default signal handling function returns. This is our ACK / notification for the successful return of the programs "suspend handler". The kernel module (if such exists) could be notified about that for instance by a simple notifier hook within kernelspace. I mean if I see this right, the "two-way" is just for the ACK isn't it?
Best regards, Daniel
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