summaryrefslogtreecommitdiff
path: root/recipes/linux/linux-handhelds-2.6-2.6.21/0001-time-prevent-the-loop-in-timespec_add_ns-from-bei.patch
blob: ad10b67639bb046f8b9d4a50ccc601428125e118 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
From 38332cb98772f5ea757e6486bed7ed0381cb5f98 Mon Sep 17 00:00:00 2001
From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Tue, 4 Mar 2008 14:59:54 -0800
Subject: [PATCH] time: prevent the loop in timespec_add_ns() from being optimised away

Since some architectures don't support __udivdi3().

Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/time.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/include/linux/time.h b/include/linux/time.h
index 2091a19..d32ef0a 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -174,6 +174,10 @@ static inline void timespec_add_ns(struct timespec *a, u64 ns)
 {
 	ns += a->tv_nsec;
 	while(unlikely(ns >= NSEC_PER_SEC)) {
+		/* The following asm() prevents the compiler from
+		 * optimising this loop into a modulo operation.  */
+		asm("" : "+r"(ns));
+
 		ns -= NSEC_PER_SEC;
 		a->tv_sec++;
 	}
-- 
1.6.0.6