Messages in this thread Patch in this message | | | Subject | [Patch 1/7] timespec diff utility | From | Shailabh Nagar <> | Date | Mon, 27 Feb 2006 03:02:47 -0500 |
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nstimestamp_diff.patch
Add kernel utility function for measuring the interval (diff) between two timespec values, adjusting for overflow
Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
include/linux/time.h | 14 ++++++++++++++ 1 files changed, 14 insertions(+)
Index: linux-2.6.16-rc4/include/linux/time.h =================================================================== --- linux-2.6.16-rc4.orig/include/linux/time.h 2006-02-27 01:20:04.000000000 -0500 +++ linux-2.6.16-rc4/include/linux/time.h 2006-02-27 01:52:49.000000000 -0500 @@ -147,6 +147,20 @@ extern struct timespec ns_to_timespec(co */ extern struct timeval ns_to_timeval(const nsec_t nsec); +/* + * timespec_diff_ns - Return difference of two timestamps in nanoseconds + * In the rare case of @end being earlier than @start, return zero + */ +static inline nsec_t timespec_diff_ns(struct timespec *start, struct timespec *end) +{ + nsec_t ret; + + ret = (nsec_t)(end->tv_sec - start->tv_sec)*NSEC_PER_SEC; + ret += (nsec_t)(end->tv_nsec - start->tv_nsec); + if (ret < 0) + return 0; + return ret; +} #endif /* __KERNEL__ */ #define NFDBITS __NFDBITS
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