diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2013-01-28 10:03:54 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2013-01-28 10:06:47 +0000 |
| commit | 3c18bae20ee2fea24d75f6986390ef8157d0207d (patch) | |
| tree | 2c4994d8ce10a5f112ebd47d0e1655d7e63c94a6 /perf | |
| parent | d9d5adec256b3935e4f261d81c37c77a2649248b (diff) | |
perf; Do not allow the backends to optimize away the clear before sync
The importance of writing to the scratch surface before retrieving an
image is that it makes that the write lands in the server queue, as well
as the GetImage, in order to serialise the timer against all the
operations.
Reported-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'perf')
| -rw-r--r-- | perf/cairo-perf-trace.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/perf/cairo-perf-trace.c b/perf/cairo-perf-trace.c index 4b8c85ea..f27f8e44 100644 --- a/perf/cairo-perf-trace.c +++ b/perf/cairo-perf-trace.c @@ -171,10 +171,12 @@ done: } static void -clear_surface (cairo_surface_t *surface) +fill_surface (cairo_surface_t *surface) { cairo_t *cr = cairo_create (surface); - cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR); + /* This needs to be an operation that the backends can't optimise away */ + cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5); + cairo_set_operator (cr, CAIRO_OPERATOR_OVER); cairo_paint (cr); cairo_destroy (cr); } @@ -714,6 +716,8 @@ cairo_perf_trace (cairo_perf_t *perf, 1, 1, CAIRO_BOILERPLATE_MODE_PERF, &args.closure); + fill_surface(args.surface); /* remove any clear flags */ + if (perf->observe) { cairo_surface_t *obs; obs = cairo_surface_create_observer (args.surface, @@ -768,7 +772,7 @@ cairo_perf_trace (cairo_perf_t *perf, fill[i] = _cairo_time_from_s (1.e-9 * cairo_device_observer_fill_elapsed (observer)); glyphs[i] = _cairo_time_from_s (1.e-9 * cairo_device_observer_glyphs_elapsed (observer)); } else { - clear_surface (args.surface); /* queue a write to the sync'ed surface */ + fill_surface (args.surface); /* queue a write to the sync'ed surface */ cairo_perf_timer_stop (); times[i] = cairo_perf_timer_elapsed (); } |