wsim: Add a small tolerance to rt balancing
Discard the low cycles when comparing queue length between engines as we
expect a small amount of instabilty. The threshold is chosen to be
around 50us.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/benchmarks/gem_wsim.c b/benchmarks/gem_wsim.c
index 3da8499..12be82e 100644
--- a/benchmarks/gem_wsim.c
+++ b/benchmarks/gem_wsim.c
@@ -827,6 +827,9 @@
qd[VCS2]);
#endif
+ qd[VCS1] >>= 10;
+ qd[VCS2] >>= 10;
+
if (qd[VCS1] < qd[VCS2])
n = 0;
else if (qd[VCS2] < qd[VCS1])
@@ -1288,6 +1291,40 @@
return mode;
}
+static void init_clocks(void)
+{
+ struct timespec t_start, t_end;
+ uint32_t rcs_start, rcs_end;
+ double overhead, t;
+
+ intel_register_access_init(intel_get_pci_device(), false, fd);
+
+ if (quiet)
+ return;
+
+ clock_gettime(CLOCK_MONOTONIC, &t_start);
+ for (int i = 0; i < 100; i++)
+ rcs_start = *REG(RCS_TIMESTAMP);
+ clock_gettime(CLOCK_MONOTONIC, &t_end);
+ overhead = 2 * elapsed(&t_start, &t_end) / 100;
+
+ clock_gettime(CLOCK_MONOTONIC, &t_start);
+ for (int i = 0; i < 100; i++)
+ clock_gettime(CLOCK_MONOTONIC, &t_end);
+ clock_gettime(CLOCK_MONOTONIC, &t_end);
+ overhead += elapsed(&t_start, &t_end) / 100;
+
+ clock_gettime(CLOCK_MONOTONIC, &t_start);
+ rcs_start = *REG(RCS_TIMESTAMP);
+ usleep(100);
+ rcs_end = *REG(RCS_TIMESTAMP);
+ clock_gettime(CLOCK_MONOTONIC, &t_end);
+
+ t = elapsed(&t_start, &t_end) - overhead;
+ printf("%d cycles in %.1fus, i.e. 1024 cycles takes %1.fus\n",
+ rcs_end - rcs_start, 1e6*t, 1024e6 * t / (rcs_end - rcs_start));
+}
+
int main(int argc, char **argv)
{
unsigned int repeat = 1;
@@ -1305,7 +1342,7 @@
int i, c;
fd = drm_open_driver(DRIVER_INTEL);
- intel_register_access_init(intel_get_pci_device(), false, fd);
+ init_clocks();
while ((c = getopt(argc, argv, "q2RSc:n:r:xw:W:t:b:h")) != -1) {
switch (c) {