[PATCH] drm/amdgpu: fix ocl test performance drop

Deucher, Alexander Alexander.Deucher at amd.com
Tue May 23 17:51:33 UTC 2017


> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Flora Cui
> Sent: Thursday, May 18, 2017 11:37 PM
> To: Christian K�nig
> Cc: amd-gfx at lists.freedesktop.org
> Subject: Re: [PATCH] drm/amdgpu: fix ocl test performance drop
> 
> btw, what's about gfx9 for amdgpu_vm_ring_has_compute_vm_bug()? Is
> the
> workaround still needed?

Gfx9 is not affected by that issue.

Alex

> 
> On Fri, May 19, 2017 at 10:25:19AM +0800, Flora Cui wrote:
> > On Thu, May 18, 2017 at 01:38:15PM +0200, Christian König wrote:
> > > Am 18.05.2017 um 09:45 schrieb Flora Cui:
> > > >partial revert commit <6971d3d> - drm/amdgpu: cleanup logic in
> > > >amdgpu_vm_flush
> > > >
> > > >Change-Id: Iadce9d613dfe9a739643a74050cea55854832adb
> > > >Signed-off-by: Flora Cui <Flora.Cui at amd.com>
> > >
> > > I don't see how the revert should be faster than the original.
> > >
> > > Especially that amdgpu_vm_had_gpu_reset() is now called twice sounds
> like
> > > more overhead than necessary.
> > >
> > > Please explain further.
> > >
> > > Christian.
> > >
> > > >---
> > > >  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 14 +++++---------
> > > >  1 file changed, 5 insertions(+), 9 deletions(-)
> > > >
> > > >diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > >index 88420dc..a96bad6 100644
> > > >--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > >+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > >@@ -743,23 +743,19 @@ int amdgpu_vm_flush(struct amdgpu_ring
> *ring, struct amdgpu_job *job)
> > > >  		id->gws_size != job->gws_size ||
> > > >  		id->oa_base != job->oa_base ||
> > > >  		id->oa_size != job->oa_size);
> > > >-	bool vm_flush_needed = job->vm_needs_flush ||
> > > >-		amdgpu_vm_ring_has_compute_vm_bug(ring);
> > > >  	unsigned patch_offset = 0;
> > > >  	int r;
> > > >-	if (amdgpu_vm_had_gpu_reset(adev, id)) {
> > > >-		gds_switch_needed = true;
> > > >-		vm_flush_needed = true;
> > > >-	}
> > > >-
> > > >-	if (!vm_flush_needed && !gds_switch_needed)
> > > >+	if (!job->vm_needs_flush && !gds_switch_needed &&
> > > >+	    !amdgpu_vm_had_gpu_reset(adev, id) &&
> > > >+	    !amdgpu_vm_ring_has_compute_vm_bug(ring))
> > > >  		return 0;
> > > >  	if (ring->funcs->init_cond_exec)
> > > >  		patch_offset = amdgpu_ring_init_cond_exec(ring);
> > > >-	if (ring->funcs->emit_vm_flush && vm_flush_needed) {
> > [flora]: for compute ring & amdgpu_vm_ring_has_compute_vm_bug(), a
> vm_flush is
> > inserted. This might cause performance drop.
> > > >+	if (ring->funcs->emit_vm_flush &&
> > > >+	    (job->vm_needs_flush || amdgpu_vm_had_gpu_reset(adev, id)))
> {
> > > >  		struct fence *fence;
> > > >  		trace_amdgpu_vm_flush(ring, job->vm_id, job-
> >vm_pd_addr);
> > >
> > >
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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