> -----Original Message----- > From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Sent: Friday, August 9, 2019 4:35 PM > To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>; Winiarski, Michal > <michal.winiarski@xxxxxxxxx>; Bloomfield, Jon <jon.bloomfield@xxxxxxxxx> > Subject: Re: [PATCH 5/5] drm/i915: Cancel non-persistent contexts on close > > Quoting Chris Wilson (2019-08-06 14:47:25) > > Normally, we rely on our hangcheck to prevent persistent batches from > > hogging the GPU. However, if the user disables hangcheck, this mechanism > > breaks down. Despite our insistence that this is unsafe, the users are > > equally insistent that they want to use endless batches and will disable > > the hangcheck mechanism. We are looking are perhaps replacing hangcheck > > with a softer mechanism, that sends a pulse down the engine to check if > > it is well. We can use the same preemptive pulse to flush an active > > persistent context off the GPU upon context close, preventing resources > > being lost and unkillable requests remaining on the GPU, after process > > termination. To avoid changing the ABI and accidentally breaking > > existing userspace, we make the persistence of a context explicit and > > enable it by default. Userspace can opt out of persistent mode (forcing > > requests to be cancelled when the context is closed by process > > termination or explicitly) by a context parameter, or to facilitate > > existing use-cases by disabling hangcheck (i915.enable_hangcheck=0). > > (Note, one of the outcomes for supporting endless mode will be the > > removal of hangchecking, at which point opting into persistent mode will > > be mandatory, or maybe the default.) > > For the record, I've finally run into examples of desktop clients > exiting before their rendering is shown. No longer hypothetical. > -Chris Can you share any details - Might be useful for testing. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
