Re: [Intel-gfx] [PATCH 2/2] drm/i915: Embellish wait_end trace

2014-07-30 Thread Chris Wilson
On Tue, Jul 29, 2014 at 01:14:30PM -0700, Ben Widawsky wrote:
 This adds two new data points to the trace event, wait time, and whether
 or not the event slept. Both of these should already be obtainable
 through various means. This patch just makes the data more accessible.

Right, the key point is that since the advent of the wait_begin/_end
pair is that we now allow concurrent non-blocking waits.
 
 Wait is obtainable with the current code by matching seqnos in
 begin/end. In simple cases where begin/ends are always paired, this is
 trivial. However, if you queue up multiple begins/ends, it can get
 confusing. We're already calculating wait time, so it's trivially added
 here. This patch also provides the slightly more accurate wait_time as
 opposed to the timestamps from the tracepoint. It's observable, but just
 noise.
 
 The second bit of information, whether or not the operation slept is
 helpful in determining where time went. This is probably also obtainable
 through the scheduler events. However, we have the information easily at
 our fingertips, we may as well give it out.
 
 This results in an event which looks like:
 gem_gtt_hog   409 [000]32.012641: i915:i915_gem_request_wait_end: dev=0, 
 ring=3, seqno=4294963203, duration=0.000368225 (slept=yes)
 
 While here, rename sleep_time to wait_time since the verb sleep hasn't
 been true for a long time (several conditions exist where it won't
 sleep).
 
 Signed-off-by: Ben Widawsky b...@bwidawsk.net

Other than the debate in the earlier patch, this looks fine.
-Chris

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Re: [Intel-gfx] [PATCH 2/2] drm/i915: Embellish wait_end trace

2014-07-30 Thread Ben Widawsky
On Wed, Jul 30, 2014 at 07:19:26AM +0100, Chris Wilson wrote:
 On Tue, Jul 29, 2014 at 01:14:30PM -0700, Ben Widawsky wrote:
  This adds two new data points to the trace event, wait time, and whether
  or not the event slept. Both of these should already be obtainable
  through various means. This patch just makes the data more accessible.
 
 Right, the key point is that since the advent of the wait_begin/_end
 pair is that we now allow concurrent non-blocking waits.
  
  Wait is obtainable with the current code by matching seqnos in
  begin/end. In simple cases where begin/ends are always paired, this is
  trivial. However, if you queue up multiple begins/ends, it can get
  confusing. We're already calculating wait time, so it's trivially added
  here. This patch also provides the slightly more accurate wait_time as
  opposed to the timestamps from the tracepoint. It's observable, but just
  noise.
  
  The second bit of information, whether or not the operation slept is
  helpful in determining where time went. This is probably also obtainable
  through the scheduler events. However, we have the information easily at
  our fingertips, we may as well give it out.
  
  This results in an event which looks like:
  gem_gtt_hog   409 [000]32.012641: i915:i915_gem_request_wait_end: 
  dev=0, ring=3, seqno=4294963203, duration=0.000368225 (slept=yes)
  
  While here, rename sleep_time to wait_time since the verb sleep hasn't
  been true for a long time (several conditions exist where it won't
  sleep).
  
  Signed-off-by: Ben Widawsky b...@bwidawsk.net
 
 Other than the debate in the earlier patch, this looks fine.
 -Chris
 

I actually don't think wait_begin is a terribly interesting event after
this patch BTW, but I didn't want to rock the boat too much. If you
agree, I can send that one as well.

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Re: [Intel-gfx] [PATCH 2/2] drm/i915: Embellish wait_end trace

2014-07-30 Thread Chris Wilson
On Tue, Jul 29, 2014 at 11:33:43PM -0700, Ben Widawsky wrote:
 On Wed, Jul 30, 2014 at 07:19:26AM +0100, Chris Wilson wrote:
  On Tue, Jul 29, 2014 at 01:14:30PM -0700, Ben Widawsky wrote:
   This adds two new data points to the trace event, wait time, and whether
   or not the event slept. Both of these should already be obtainable
   through various means. This patch just makes the data more accessible.
  
  Right, the key point is that since the advent of the wait_begin/_end
  pair is that we now allow concurrent non-blocking waits.
   
   Wait is obtainable with the current code by matching seqnos in
   begin/end. In simple cases where begin/ends are always paired, this is
   trivial. However, if you queue up multiple begins/ends, it can get
   confusing. We're already calculating wait time, so it's trivially added
   here. This patch also provides the slightly more accurate wait_time as
   opposed to the timestamps from the tracepoint. It's observable, but just
   noise.
   
   The second bit of information, whether or not the operation slept is
   helpful in determining where time went. This is probably also obtainable
   through the scheduler events. However, we have the information easily at
   our fingertips, we may as well give it out.
   
   This results in an event which looks like:
   gem_gtt_hog   409 [000]32.012641: i915:i915_gem_request_wait_end: 
   dev=0, ring=3, seqno=4294963203, duration=0.000368225 (slept=yes)
   
   While here, rename sleep_time to wait_time since the verb sleep hasn't
   been true for a long time (several conditions exist where it won't
   sleep).
   
   Signed-off-by: Ben Widawsky b...@bwidawsk.net
  
  Other than the debate in the earlier patch, this looks fine.
  -Chris
  
 
 I actually don't think wait_begin is a terribly interesting event after
 this patch BTW, but I didn't want to rock the boat too much. If you
 agree, I can send that one as well.

The only advantage is that wait_begin is before the wait, which may be
significant - espcially in a time based profile.
-Chris

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[Intel-gfx] [PATCH 2/2] drm/i915: Embellish wait_end trace

2014-07-29 Thread Ben Widawsky
This adds two new data points to the trace event, wait time, and whether
or not the event slept. Both of these should already be obtainable
through various means. This patch just makes the data more accessible.

Wait is obtainable with the current code by matching seqnos in
begin/end. In simple cases where begin/ends are always paired, this is
trivial. However, if you queue up multiple begins/ends, it can get
confusing. We're already calculating wait time, so it's trivially added
here. This patch also provides the slightly more accurate wait_time as
opposed to the timestamps from the tracepoint. It's observable, but just
noise.

The second bit of information, whether or not the operation slept is
helpful in determining where time went. This is probably also obtainable
through the scheduler events. However, we have the information easily at
our fingertips, we may as well give it out.

This results in an event which looks like:
gem_gtt_hog   409 [000]32.012641: i915:i915_gem_request_wait_end: dev=0, 
ring=3, seqno=4294963203, duration=0.000368225 (slept=yes)

While here, rename sleep_time to wait_time since the verb sleep hasn't
been true for a long time (several conditions exist where it won't
sleep).

Signed-off-by: Ben Widawsky b...@bwidawsk.net
---
 drivers/gpu/drm/i915/i915_gem.c   | 12 +++-
 drivers/gpu/drm/i915/i915_trace.h | 29 ++---
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 17f7ac9..bb7fed6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1161,6 +1161,8 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 
seqno,
struct timespec before, now;
DEFINE_WAIT(wait);
unsigned long timeout_expire;
+   struct timespec wait_time;
+   bool slept = false;
int ret;
 
WARN(!intel_irqs_enabled(dev_priv), IRQs disabled);
@@ -1216,6 +1218,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 
seqno,
break;
}
 
+   slept = true;
timer.function = NULL;
if (timeout || missed_irq(dev_priv, ring)) {
unsigned long expire;
@@ -1233,17 +1236,16 @@ static int __wait_seqno(struct intel_engine_cs *ring, 
u32 seqno,
}
}
getrawmonotonic(now);
-   trace_i915_gem_request_wait_end(ring, seqno);
 
if (!irq_test_in_progress)
ring-irq_put(ring);
 
finish_wait(ring-irq_queue, wait);
+   wait_time = timespec_sub(now, before);
+   trace_i915_gem_request_wait_end(ring, seqno, wait_time, slept);
 
-   if (timeout) {
-   struct timespec sleep_time = timespec_sub(now, before);
-   *timeout = timespec_sub(*timeout, sleep_time);
-   }
+   if (timeout)
+   *timeout = timespec_sub(*timeout, wait_time);
 
return ret;
 }
diff --git a/drivers/gpu/drm/i915/i915_trace.h 
b/drivers/gpu/drm/i915/i915_trace.h
index f5aa006..0936066 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -476,9 +476,32 @@ TRACE_EVENT(i915_gem_request_wait_begin,
  __entry-blocking ?  yes (NB) : no)
 );
 
-DEFINE_EVENT(i915_gem_request, i915_gem_request_wait_end,
-   TP_PROTO(struct intel_engine_cs *ring, u32 seqno),
-   TP_ARGS(ring, seqno)
+TRACE_EVENT(i915_gem_request_wait_end,
+   TP_PROTO(struct intel_engine_cs *ring, u32 seqno, struct timespec 
delta, bool slept),
+   TP_ARGS(ring, seqno, delta, slept),
+
+   TP_STRUCT__entry(
+__field(u32, dev)
+__field(u32, ring)
+__field(u32, seqno)
+__field(long long, s)
+__field(long, ns)
+__field(bool, slept)
+),
+
+   TP_fast_assign(
+  __entry-dev = ring-dev-primary-index;
+  __entry-ring = ring-id;
+  __entry-seqno = seqno;
+  __entry-s = (long long)delta.tv_sec;
+  __entry-ns = delta.tv_nsec;
+  __entry-slept = slept;
+  ),
+
+   TP_printk(dev=%u, ring=%u, seqno=%u, duration=%lld.%.9ld 
(slept=%s),
+ __entry-dev, __entry-ring, __entry-seqno,
+ __entry-s, __entry-ns,
+ __entry-slept ?  yes : no)
 );
 
 DECLARE_EVENT_CLASS(i915_ring,
-- 
2.0.2

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