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 <ben@xxxxxxxxxxxx> > > > > 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 -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
