From: Dmitry Adamushko <dmitry.adamushko@gmail.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
dmitry.adamushko@gmail.com
Subject: latencytop: optimize LT_BACKTRACEDEPTH loops a bit
Date: Sat, 02 Feb 2008 23:59:31 +0100 [thread overview]
Message-ID: <1201993171.12880.8.camel@earth> (raw)
Subject: latencytop: optimize LT_BACKTRACEDEPTH loops a bit.
It looks like there is no need to loop any longer when 'same == 0'.
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index b4e3c85..61f7da0 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -64,8 +64,8 @@ account_global_scheduler_latency(struct task_struct *tsk, struct latency_record
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 +73,12 @@ account_global_scheduler_latency(struct task_struct *tsk, struct latency_record
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)
+
+ if (!same || record == 0 || record == ULONG_MAX)
break;
}
if (same) {
@@ -143,14 +143,15 @@ account_scheduler_latency(struct task_struct *tsk, int usecs, int inter)
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)
+
+ if (!same || record == 0 || record == ULONG_MAX)
break;
}
if (same) {
next reply other threads:[~2008-02-02 23:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-02 22:59 Dmitry Adamushko [this message]
2008-02-03 0:11 ` latencytop: optimize LT_BACKTRACEDEPTH loops a bit Arjan van de Ven
-- strict thread matches above, loose matches on Subject: below --
2008-02-03 21:33 Dmitry Adamushko
2008-02-04 4:31 ` Arjan van de Ven
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