On Thu, Dec 12, 2013 at 11:08:47AM +0000, Chris Wilson wrote: > On Fri, Dec 06, 2013 at 02:11:22PM -0800, Ben Widawsky wrote: > > From: Ben Widawsky <ben@xxxxxxxxxxxx> > > > > With context destruction, we always want to be able to tear down the > > underlying address space. This is invoked on the last unreference to the > > context which could happen before we've moved all objects to the > > inactive list. To enable a clean tear down the address space, make sure > > to process the request free lastly. > > > > Without this change, we cannot guarantee to we don't still have active > > objects in the VM. > > > > As an example of a failing case: > > CTX-A is created, count=1 > > CTX-A is used during execbuf > > does a context switch count = 2 > > and add_request count = 3 > > CTX B runs, switches, CTX-A count = 2 > > CTX-A is destroyed, count = 1 > > retire requests is called > > free_request from CTX-A, count = 0 <--- free context with active object > > > > As mentioned above, by doing the free request after processing the > > active list, we can avoid this case. > > So just process the active_list first, the requests and objects > associated with the ring should be fairly independent. Also, stuff like this needs a testcase, and I didn't spot such a thing in the patches posted thus far. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
