Messages in this thread Patch in this message | | | From | Segher Boessenkool <> | Subject | [PATCH] Prevent the loop in timespec_add_ns() to be optimised away | Date | Fri, 22 Feb 2008 22:40:45 +0100 |
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...since some architectures don't support __udivdi3() (and we don't want to use that, anyway).
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> --- 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++; } -- 1.5.4.2.184.gb23b
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