On Wed, 6 Jul 2011 15:14:53 -0700, Ben Widawsky <b...@bwidawsk.net> wrote: > bool i915_enable_hangcheck __read_mostly = true; > module_param_named(enable_hangcheck, i915_enable_hangcheck, bool, 0644); > +MODULE_PARM_DESC(enable_hangcheck, "Periodically check GPU activity for " > + "detecting hangs (default: true)");
I think we need to stress here that disabling the hangcheck can cause the system to hang (X, VT switching, etc) following an GPU hang. The assumption that the hangcheck will prevail and break any waits (and eventually release the struct_mutex) is deeply ingrained into the code. The alternate scenario is to wait without the mutex, which then requires revalidating all state after a wait, effectively we would have to restart the operation from the being. And introduces unfairness (potential starvation) into command/resource allocations... -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
