Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: [RFD] Automatic suspend | Date | Sat, 21 Feb 2009 00:20:43 +0100 |
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Am Samstag 21 Februar 2009 00:11:28 schrieb Arve Hjønnevåg: > On Fri, Feb 20, 2009 at 2:05 PM, Oliver Neukum <oliver@neukum.org> wrote: > > Am Freitag 20 Februar 2009 11:46:55 schrieb Rafael J. Wysocki: > >> On Thursday 19 February 2009, Oliver Neukum wrote:
> > With the set of runnable processes.There's always a window between > > evaluating the current set of runnable tasks and telling the kernel to > > sleep. IMO the most elegant solution would be a task attribute that would > > signal the kernel that a task should not count as keeping the system busy > > even if it is runnable and trigger the sleep in kernel space. > > It is not always safe to enter suspend when no tasks are runnable. For > instance, a key event could be on a user space queue, but the code > that reads from that queue has been paged out.
In that case you'd have a task waiting for IO. The driver should refuse to suspend or wake up the system as IO is completed. It may be inefficient to suspend for such a presumably short time, but it is not a correctness issue.
Regards Oliver
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