From f3fd37683cc406ffaccf097de0433130c85c8651 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Thu, 24 May 2012 15:03:09 -0700 Subject: [PATCH] drm/i915: improve i915_wait_request_begin trace The trace events adds whether or not the wait was blocking. Blocking in this case means to hold struct_mutex (ie. no new work can be submitted during the wait). The information is inherently racy. The blocking information is racy since mutex_is_locked doesn't check that the current thread holds the lock. The only other option would be to pass the boolean information of whether or not the class was blocking down through the stack which is less desirable. v2: Don't do a trace event per loop. (Chris) Only get blocking/non-blocking info (Chris) v3: updated comment in code as well as commit msg (Daniel) Add "(NB)" to trace information to remind us in 6 months (Ben) Signed-off-by: Ben Widawsky Reviewed-by: Eugeni Dodonov Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_trace.h | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index dac7bba4d9d..fe90b3a84a6 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -311,9 +311,33 @@ DEFINE_EVENT(i915_gem_request, i915_gem_request_retire, TP_ARGS(ring, seqno) ); -DEFINE_EVENT(i915_gem_request, i915_gem_request_wait_begin, +TRACE_EVENT(i915_gem_request_wait_begin, TP_PROTO(struct intel_ring_buffer *ring, u32 seqno), - TP_ARGS(ring, seqno) + TP_ARGS(ring, seqno), + + TP_STRUCT__entry( + __field(u32, dev) + __field(u32, ring) + __field(u32, seqno) + __field(bool, blocking) + ), + + /* NB: the blocking information is racy since mutex_is_locked + * doesn't check that the current thread holds the lock. The only + * other option would be to pass the boolean information of whether + * or not the class was blocking down through the stack which is + * less desirable. + */ + TP_fast_assign( + __entry->dev = ring->dev->primary->index; + __entry->ring = ring->id; + __entry->seqno = seqno; + __entry->blocking = mutex_is_locked(&ring->dev->struct_mutex); + ), + + TP_printk("dev=%u, ring=%u, seqno=%u, blocking=%s", + __entry->dev, __entry->ring, __entry->seqno, + __entry->blocking ? "yes (NB)" : "no") ); DEFINE_EVENT(i915_gem_request, i915_gem_request_wait_end,