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* [PATCH] drm/i915: Add a tracepoint for using a semaphore
@ 2013-08-26 12:46 Chris Wilson
  2013-08-26 13:20 ` Ville Syrjälä
  0 siblings, 1 reply; 7+ messages in thread
From: Chris Wilson @ 2013-08-26 12:46 UTC (permalink / raw)
  To: intel-gfx

So that we can find the callers who introduce a ring stall. A single
ring stall is not too unwelcome, the right issue becomes when they start
to interlock and prevent any concurrent work. That, however, is a little
tricker to detect with a mere tracepoint!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c   |  2 ++
 drivers/gpu/drm/i915/i915_trace.h | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 85537d1..0122278 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2698,6 +2698,8 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (ret)
 		return ret;
 
+	trace_i915_gem_object_sync(obj, to);
+
 	ret = to->sync_to(to, from, seqno);
 	if (!ret)
 		/* We use last_read_seqno because sync_to()
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index feaacbb..728c43b 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -33,6 +33,25 @@ TRACE_EVENT(i915_gem_object_create,
 	    TP_printk("obj=%p, size=%u", __entry->obj, __entry->size)
 );
 
+TRACE_EVENT(i915_gem_object_sync,
+	    TP_PROTO(struct drm_i915_gem_object *obj, struct intel_ring_buffer *to),
+	    TP_ARGS(obj, to),
+
+	    TP_STRUCT__entry(
+			     __field(struct drm_i915_gem_object *, obj)
+			     __field(u32, sync_from)
+			     __field(u32, sync_to)
+			     ),
+
+	    TP_fast_assign(
+			   __entry->obj = obj;
+			   __entry->sync_from = obj->ring->id;
+			   __entry->sync_to = to->id;
+			   ),
+
+	    TP_printk("obj=%p, sync-from=%u, sync-to=%u", __entry->obj, __entry->sync_from, __entry->sync_to)
+);
+
 TRACE_EVENT(i915_vma_bind,
 	    TP_PROTO(struct i915_vma *vma, bool mappable),
 	    TP_ARGS(vma, mappable),
-- 
1.8.4.rc3

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* [PATCH] drm/i915: Add a tracepoint for using a semaphore
@ 2013-08-26 13:34 Chris Wilson
  0 siblings, 0 replies; 7+ messages in thread
From: Chris Wilson @ 2013-08-26 13:34 UTC (permalink / raw)
  To: intel-gfx

So that we can find the callers who introduce a ring stall. A single
ring stall is not too unwelcome, the right issue becomes when they start
to interlock and prevent any concurrent work. That, however, is a little
tricker to detect with a mere tracepoint!

v2: Rebrand it as a ring event, rather than an object event.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c   |  2 ++
 drivers/gpu/drm/i915/i915_trace.h | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 85537d1..a9a6baa 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2698,6 +2698,8 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (ret)
 		return ret;
 
+	trace_i915_gem_ring_sync_to(from, to);
+
 	ret = to->sync_to(to, from, seqno);
 	if (!ret)
 		/* We use last_read_seqno because sync_to()
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index feaacbb..163774a 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -235,6 +235,25 @@ TRACE_EVENT(i915_gem_evict_everything,
 	    TP_printk("dev=%d", __entry->dev)
 );
 
+TRACE_EVENT(i915_gem_ring_sync_to,
+	    TP_PROTO(struct intel_ring_buffer *from, struct intel_ring_buffer *to),
+	    TP_ARGS(from, to),
+
+	    TP_STRUCT__entry(
+			     __field(u32, dev)
+			     __field(u32, sync_from)
+			     __field(u32, sync_to)
+			     ),
+
+	    TP_fast_assign(
+			   __entry->dev = from->dev->primary->index;
+			   __entry->sync_from = from->id;
+			   __entry->sync_to = to->id;
+			   ),
+
+	    TP_printk("dev=%u, sync-from=%u, sync-to=%u", __entry->dev, __entry->sync_from, __entry->sync_to)
+);
+
 TRACE_EVENT(i915_gem_ring_dispatch,
 	    TP_PROTO(struct intel_ring_buffer *ring, u32 flags),
 	    TP_ARGS(ring, flags),
-- 
1.8.4.rc3

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH 09/13] drm/i915: Add a tracepoint for using a semaphore
@ 2013-09-25 10:11 Daniel Vetter
  2013-09-25 10:43 ` [PATCH] " Chris Wilson
  0 siblings, 1 reply; 7+ messages in thread
From: Daniel Vetter @ 2013-09-25 10:11 UTC (permalink / raw)
  To: Ville Syrjälä; +Cc: intel-gfx

On Wed, Sep 25, 2013 at 12:34:37PM +0300, Ville Syrjälä wrote:
> On Mon, Sep 23, 2013 at 05:33:26PM -0300, Rodrigo Vivi wrote:
> > From: Chris Wilson <chris@chris-wilson.co.uk>
> > 
> > So that we can find the callers who introduce a ring stall. A single
> > ring stall is not too unwelcome, the right issue becomes when they start
> > to interlock and prevent any concurrent work. That, however, is a little
> > tricker to detect with a mere tracepoint!
> > 
> > v2: Rebrand it as a ring event, rather than an object event.
> > 
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
> 
> Just wondering if we would want to see the seqno(s) in the trace as well?

Hm yeah, I guess the seqno we're syncing on the from ring would be useful
to gauge how much parallelism there really is. Chris, care to respin?
-Daniel

> 
> But anyway, the patch looks fine.
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> > ---
> >  drivers/gpu/drm/i915/i915_gem.c   |  2 ++
> >  drivers/gpu/drm/i915/i915_trace.h | 19 +++++++++++++++++++
> >  2 files changed, 21 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> > index d68cc5c..4a16491 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -2614,6 +2614,8 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
> >  	if (ret)
> >  		return ret;
> >  
> > +	trace_i915_gem_ring_sync_to(from, to);
> > +
> >  	ret = to->sync_to(to, from, seqno);
> >  	if (!ret)
> >  		/* We use last_read_seqno because sync_to()
> > diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
> > index 5c8e36a..48e8f07 100644
> > --- a/drivers/gpu/drm/i915/i915_trace.h
> > +++ b/drivers/gpu/drm/i915/i915_trace.h
> > @@ -233,6 +233,25 @@ TRACE_EVENT(i915_gem_evict_everything,
> >  	    TP_printk("dev=%d", __entry->dev)
> >  );
> >  
> > +TRACE_EVENT(i915_gem_ring_sync_to,
> > +	    TP_PROTO(struct intel_ring_buffer *from, struct intel_ring_buffer *to),
> > +	    TP_ARGS(from, to),
> > +
> > +	    TP_STRUCT__entry(
> > +			     __field(u32, dev)
> > +			     __field(u32, sync_from)
> > +			     __field(u32, sync_to)
> > +			     ),
> > +
> > +	    TP_fast_assign(
> > +			   __entry->dev = from->dev->primary->index;
> > +			   __entry->sync_from = from->id;
> > +			   __entry->sync_to = to->id;
> > +			   ),
> > +
> > +	    TP_printk("dev=%u, sync-from=%u, sync-to=%u", __entry->dev, __entry->sync_from, __entry->sync_to)
> > +);
> > +
> >  TRACE_EVENT(i915_gem_ring_dispatch,
> >  	    TP_PROTO(struct intel_ring_buffer *ring, u32 flags),
> >  	    TP_ARGS(ring, flags),
> > -- 
> > 1.8.1.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel OTC
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2013-09-25 11:30 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2013-08-26 12:46 [PATCH] drm/i915: Add a tracepoint for using a semaphore Chris Wilson
2013-08-26 13:20 ` Ville Syrjälä
2013-08-26 13:30   ` Chris Wilson
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2013-08-26 13:34 Chris Wilson
2013-09-25 10:11 [PATCH 09/13] " Daniel Vetter
2013-09-25 10:43 ` [PATCH] " Chris Wilson
2013-09-25 11:29   ` Ville Syrjälä
2013-09-25 11:31     ` Daniel Vetter

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