[igt-dev] [PATCH i-g-t v2 2/4] scripts/trace.pl: Sort order

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

Add an extra level to the databse key sort so that the ordering is
deterministic. If the time stamp matches, it now compares the key
itself as well (context/seqno). This makes it much easier to determine
if a change has actually broken anything. Previously back to back runs
with no changes could still produce different output, especially when
adding extra debug output during the calculations.

As the comparison test is now more than a single equation, moved it
out into a separate sort function.

v2: Re-work sort func for readability/performance [Tvrtko]

Signed-off-by: John Harrison <John.C.Harrison at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 scripts/trace.pl | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/scripts/trace.pl b/scripts/trace.pl
index a73fcf38..b528d482 100755
--- a/scripts/trace.pl
+++ b/scripts/trace.pl
@@ -539,7 +539,29 @@ my (%submit_avg, %execute_avg, %ctxsave_avg);
 my $last_ts = 0;
 my $first_ts;
 
-my @sorted_keys = sort {$db{$a}->{'start'} <=> $db{$b}->{'start'}} keys %db;
+sub sortStart {
+	my $as = $db{$a}->{'start'};
+	my $bs = $db{$b}->{'start'};
+	my $val;
+
+	$val = $as <=> $bs;
+	$val = $a cmp $b if $val == 0;
+
+	return $val;
+}
+
+sub sortQueue {
+	my $as = $db{$a}->{'queue'};
+	my $bs = $db{$b}->{'queue'};
+	my $val;
+
+	$val = $as <=> $bs;
+	$val = $a cmp $b if $val == 0;
+
+	return $val;
+}
+
+my @sorted_keys = sort sortStart keys %db;
 my $re_sort = 0;
 die "Database changed size?!" unless scalar(@sorted_keys) == $key_count;
 
@@ -588,9 +610,9 @@ foreach my $key (@sorted_keys) {
 	$ctxsave_avg{$ring} += $db{$key}->{'end'} - $db{$key}->{'notify'};
 }
 
- at sorted_keys = sort {$db{$a}->{'start'} <=> $db{$b}->{'start'}} keys %db if $re_sort;
+ at sorted_keys = sort sortStart keys %db if $re_sort;
 
-foreach my $ring (keys %batch_avg) {
+foreach my $ring (sort keys %batch_avg) {
 	$batch_avg{$ring} /= $batch_count{$ring};
 	$batch_total_avg{$ring} /= $batch_count{$ring};
 	$submit_avg{$ring} /= $batch_count{$ring};
@@ -830,7 +852,7 @@ print <<ENDHTML;
 ENDHTML
 
 my $i = 0;
-foreach my $key (sort {$db{$a}->{'queue'} <=> $db{$b}->{'queue'}} keys %db) {
+foreach my $key (sort sortQueue keys %db) {
 	my ($name, $ctx, $seqno) = ($db{$key}->{'name'}, $db{$key}->{'ctx'}, $db{$key}->{'seqno'});
 	my ($queue, $start, $notify, $end) = ($db{$key}->{'queue'}, $db{$key}->{'start'}, $db{$key}->{'notify'}, $db{$key}->{'end'});
 	my $submit = $queue + $db{$key}->{'submit-delay'};
-- 
2.15.1