Messages in this thread | | | Date | Tue, 26 Aug 2008 15:51:14 -0400 | From | Christoph Hellwig <> | Subject | Re: [PATCH 2/2] poll: allow f_op->poll to sleep |
| |
On Tue, Aug 26, 2008 at 09:58:14AM -0700, Linus Torvalds wrote: > I don't really see the point. > > poll() isn't allowed to sleep for many reasons. Some are technical. But > the most obvious one is that a sleeping "poll()" is totally against the > whole point of polling in the first place! > > So is there some big conceptual reason to change how poll() has always > worked?
Just as a little sidenote most files on spufs have a ->poll that sleeps, and currently we don't have any debugging to catch this, I just noticed this by accident. The reason that it sleeps is because it needs to grab a sleping lock, and as that lock protects against a rather complicate type of hardware context switch it's not possible to replace it with a spinlock.
| |