linux-kernel - [PATCH] sched/clock: cleanup, remove wrap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 7 May 2014 20:48:58 +0900
From:	Dongsheng Yang <yangds.fnst@...fujitsu.com>
To:	<mingo@...hat.com>, <peterz@...radead.org>
CC:	<linux-kernel@...r.kernel.org>,
	Dongsheng Yang <yangds.fnst@...fujitsu.com>
Subject: [PATCH] sched/clock: cleanup, remove wrap_{max|min}().

I am not sure why we need the wrap_{max|min}() in kernel/sched/clock.c.
But I checked the implementation of max() and min() in linux/kernel.h, I think
we can reuse them here rather than introduce a new function named
wrap_{max|min}().

Signed-off-by: Dongsheng Yang <yangds.fnst@...fujitsu.com>
---
 kernel/sched/clock.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 3ef6451..36c03a8 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -173,20 +173,6 @@ void sched_clock_init(void)
 }
 
 /*
- * min, max except they take wrapping into account
- */
-
-static inline u64 wrap_min(u64 x, u64 y)
-{
-	return (s64)(x - y) < 0 ? x : y;
-}
-
-static inline u64 wrap_max(u64 x, u64 y)
-{
-	return (s64)(x - y) > 0 ? x : y;
-}
-
-/*
  * update the percpu scd from the raw @now value
  *
  *  - filter out backward motion
@@ -212,11 +198,11 @@ again:
 	 */
 
 	clock = scd->tick_gtod + delta;
-	min_clock = wrap_max(scd->tick_gtod, old_clock);
-	max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC);
+	min_clock = max(scd->tick_gtod, old_clock);
+	max_clock = max(old_clock, scd->tick_gtod + TICK_NSEC);
 
-	clock = wrap_max(clock, min_clock);
-	clock = wrap_min(clock, max_clock);
+	clock = max(clock, min_clock);
+	clock = min(clock, max_clock);
 
 	if (cmpxchg64(&scd->clock, old_clock, clock) != old_clock)
 		goto again;
-- 
1.8.2.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/