Hi! > > Well, to me, rwsem sounds definitely better. Still, I think it's better to > > avoid locking it for too long, so we could use a variable protected by the > > rwsem such that if it's 'true', unsleepable tasks checking it will put > > themselves into a wait queue which will be woken up by the PM core > > during resume. > > Isn't that exactly what an rwsem does? When it is locked for writing > (your flag is "true"), tasks attempting to get a read lock will put > themselves into a wait queue which will be woken up when the write lock > is released (when the PM core sets the flag to "false" during resume). > > In this case we could use something a little simpler than a > general-purpose rwsem, since there will never be more than one task > getting a write lock at any time -- i.e., never more than one task > carrying out a system sleep. It's not hard to design such a simplified > rwsem in a way that exerts virtually no overhead on readers whenever no > writer is present. Just use generic rwsem... if we can see performance impact, we can optimize it later. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
