From: Segher Boessenkool Date: Tue, 4 Mar 2008 22:59:54 +0000 (-0800) Subject: time: prevent the loop in timespec_add_ns() from being optimised away X-Git-Tag: v2.6.25-rc5~2^2~2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=38332cb98772f5ea757e6486bed7ed0381cb5f98;p=linux-2.6-omap-h63xx.git time: prevent the loop in timespec_add_ns() from being optimised away Since some architectures don't support __udivdi3(). Signed-off-by: Segher Boessenkool Cc: john stultz Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- diff --git a/include/linux/time.h b/include/linux/time.h index 2091a19f165..d32ef0ad4c0 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++; }