Le 11 mai 2012 à 18:05, Jens Alfke a écrit : > > On May 9, 2012, at 7:14 AM, Ph.T wrote: > >> . in a pre-emptive OS there should be no freezing; >> given the new concurrency model >> that includes the use of the graphics processor GPU >> to do the system's non-graphics processing, > > Well, the GPU can _occasionally_ be used to do some non-graphics work, > typically tasks that are highly parallelizable. I’d reckon this happens most > often in games, less in general purpose software. > >> my current guess is that the freezes happen when >> something goes wrong in the GPU, >> and the CPU is just waiting forever . >> . the CPU needs to have some way of getting control back, >> and sending an exception message to >> any of the processes that were affected by the hung-up GPU . >> . could any of Apple's developers >> correct this theory or comment on it ? > > OS freezes tend to happen when kernel-level code gets into an infinite loop > or deadlock. Sure there “should be no freezing” but there should be no bugs > either, and that’s never true. (It’s exacerbated by the fact that some 3rd > party device drivers need to run in kernel space.) > > _Some_ system freezes are due to the GPU completely locking up, usually due > to a bug in the GPU vendor’s driver. My understanding is that when this > happens it’s not really possible for the GPU to recover without a system > reset. The CPU is probably still OK, but that doesn’t do any good if it can’t > access the display. > > —Jens
While playing with GPU programming, I had a lot of such freeze, and they never locked the CPU. I was always able to connect to my machine though SSH. Killing the processes that are affected is not enough. You may have to reinitialize the GPU driver. I think this is something Windows is able to do, but not Mac OS X AFAIK. More info about how it works on Windows can be found here: http://msdn.microsoft.com/en-us/windows/hardware/gg487368 -- Jean-Daniel _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
