2016-09-22 Christian König <christian.koenig@xxxxxxx>: > Dropping the rest of the patch, cause that really doesn't make sense any > more. > > Am 22.09.2016 um 12:40 schrieb Gustavo Padovan: > > > E.g. for example it is illegal to do something like > > > >"while(!fence_is_signaled(f)) sleep();" without enabling signaling before > > > >doing this. > > > > > > > >Could just be a misunderstanding, but the comments on your patch actually > > > >sounds a bit like somebody is trying to do exactly that. > > I think the usecase in mind here is poll(fd, timeout=0) > > Exactly as I feared. Even if userspace polls with timeout=0 you still need > to call enable_signaling(). > > Otherwise you can run into a situation where userspace only uses timeout=0 > and so never activates the signaling check in the driver. > > This would in turn result in an endless loop on implementations where the > driver never signals fences on their own. Polling is optional, userspace may never call it. And DRM/KMS or GPU drivers will be doing fence_wait() themselves so signaling is enabled at some point. Gustavo _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
