latencytop: optimize LT_BACKTRACEDEPTH loops a bit
There is no need to loop any longer when 'same == 0'.
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index b4e3c85..7c74dab 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -64,8 +64,8 @@
return;
for (i = 0; i < MAXLR; i++) {
- int q;
- int same = 1;
+ int q, same = 1;
+
/* Nothing stored: */
if (!latency_record[i].backtrace[0]) {
if (firstnonnull > i)
@@ -73,12 +73,15 @@
continue;
}
for (q = 0 ; q < LT_BACKTRACEDEPTH ; q++) {
- if (latency_record[i].backtrace[q] !=
- lat->backtrace[q])
+ unsigned long record = lat->backtrace[q];
+
+ if (latency_record[i].backtrace[q] != record) {
same = 0;
- if (same && lat->backtrace[q] == 0)
break;
- if (same && lat->backtrace[q] == ULONG_MAX)
+ }
+
+ /* 0 and ULONG_MAX entries mean end of backtrace: */
+ if (record == 0 || record == ULONG_MAX)
break;
}
if (same) {
@@ -143,14 +146,18 @@
for (i = 0; i < LT_SAVECOUNT ; i++) {
struct latency_record *mylat;
int same = 1;
+
mylat = &tsk->latency_record[i];
for (q = 0 ; q < LT_BACKTRACEDEPTH ; q++) {
- if (mylat->backtrace[q] !=
- lat.backtrace[q])
+ unsigned long record = lat.backtrace[q];
+
+ if (mylat->backtrace[q] != record) {
same = 0;
- if (same && lat.backtrace[q] == 0)
break;
- if (same && lat.backtrace[q] == ULONG_MAX)
+ }
+
+ /* 0 and ULONG_MAX entries mean end of backtrace: */
+ if (record == 0 || record == ULONG_MAX)
break;
}
if (same) {
