On Mon, May 31, 2010 at 11:38:55PM +0200, Rafael J. Wysocki wrote: > On Monday 31 May 2010, Arve Hjønnevåg wrote: > > 2010/5/29 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > > > On Sat, 29 May 2010, Arve Hjønnevåg wrote: > > > > > >> > In place of in-kernel suspend blockers, there will be a new type of QoS > > >> > constraint -- call it QOS_EVENTUALLY. It's a very weak constraint, > > >> > compatible with all cpuidle modes in which runnable threads are allowed > > >> > to run (which is all of them), but not compatible with suspend. > > >> > > > >> This sound just like another API rename. It will work, but given that > > >> suspend blockers was the name least objectionable last time around, > > >> I'm not sure what this would solve. > > > > > > It's not just a rename. By changing this into a QoS constraint, we > > > make it more generally useful. Instead of standing on its own, it > > > becomes part of the PM-QOS framework. > > > > > > > We cannot use the existing pm-qos framework. It is not safe to call > > from atomic context. > > We've just merged a patch that fixed that if I'm not mistaken. Mark, did your > PM QoS update fix that? > I'm pretty sure it can be called in atomic context, and if its not I'm sure we can fix that. It can be called in atomic context. I don't think it was ever a problem to call it in atomic context. The problem it had was that crappy list of string compares. Thats been fixed. --mgross > > Also, it does not have any state constraints, so it iterates over every > > registered constraint each time one of them changes. > > That's fixable IMO. > > > Nor does is currently provide any stats for debugging. > > That's why Alan is proposing to add that. > > > The original wakelock patchset supported a wakelock type so it could > > be used to block more then suspend, but I had to remove this because > > it "overlapped" with pm-qos. So, yes I do consider this just another > > rename. > > It's an extension of an existing framework rather than an addition of a new > one, with entirely new API and so on. Extending existing APIs is much > preferred to adding new ones, in general. > > Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
