Re: Attempted summary of suspend-blockers LKML thread
From: Arjan van de Ven <hidden>
Date: 2010-08-04 01:34:47
On Mon, 2 Aug 2010 21:56:10 -0700 Arve Hjønnevåg [off-list ref] wrote:
quoted
non-obvious dependencies.The dependencies is what made this solution uninteresting to us. For instance, we currently use cgroup scheduling to reduce the impact of some background tasks, but we occasionally saw a watchdog restart of the system process were critical services were waiting on a kernel mutex owned by a background task for more than 20 seconds. If we froze a cgroup instead, we would not hit this particular problem since tasks cannot be frozen while executing kernel code the same way they can be preempted, but nothing prevents a task from being frozen while holding a user-space resource.
one of the solutions we're looking at to solve this is to unfreeze the cgroup on a regular basis (say, every 15 to 30 seconds) briefly to avoid this kind of deadlock... -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org _______________________________________________ linux-pm mailing list linux-pm@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/linux-pm