Quoting Zhenyu Wang (2019-04-26 07:04:45) > On 2019.04.25 17:23:44 +0100, Chris Wilson wrote: > > Quoting Chris Wilson (2019-04-25 06:42:02) > > > Our eventual goal is to rid request construction of struct_mutex, with > > > the short term step of lifting the struct_mutex requirements into the > > > higher levels (i.e. the caller must ensure that the context is already > > > pinned into the GTT). In this patch, we pin GVT's shadow context upon > > > allocation and so keep them pinned into the GGTT for as long as the > > > virtual machine is alive, and so we can use the simpler request > > > construction path safe in the knowledge that the hard work is already > > > done. > > > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> > > > > Hi Zhenyu, could you check through this patch and make sure I haven't > > broken gvt in the process? > > > > The end result is that the gvt shadow context is always pinned into the > > ggtt, avoids any eviction/shrinking, and so allows gvt to use the faster > > paths for request allocation. > > > > I did found an issue with below extra change required. > > diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c > index 012564cac752..d4dc0e189547 100644 > --- a/drivers/gpu/drm/i915/gvt/scheduler.c > +++ b/drivers/gpu/drm/i915/gvt/scheduler.c > @@ -895,11 +895,6 @@ static void complete_current_workload(struct intel_gvt *gvt, int ring_id) > intel_vgpu_trigger_virtual_event(vgpu, event); > } > > - /* unpin shadow ctx as the shadow_ctx update is done */ > - mutex_lock(&rq->i915->drm.struct_mutex); > - intel_context_unpin(rq->hw_context); > - mutex_unlock(&rq->i915->drm.struct_mutex); > - > i915_request_put(fetch_and_zero(&workload->req)); > } > > Previously we tried extra pin to make sure GVT still can access shadow > context after request finish, then we did above extra unpin after done > with update to guest context. Now this is not required and actually > caused wrong unpin. Oops. I forgot to grep for rq->hw_context (and I forgot about earlier discussions for why that existed :) One less struct_mutex for the win. The end goal for this is that gvt will never need struct_mutex (nor anything else in the driver!) > With this change this series can pass my sanity test. So with this added. > > Acked-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> Ta, -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
