Re:A positive leap second will be introduced at the end of J...
by cnvogel on Monday January 05, 2015 @03:15PM
(#8840847)
Workload is pretty low in either case...
Here's the function in the Linux-Kernel that's counting the seconds. It's actually not specified if this function is called exactly every second, or more often, or less often. It just overflows accumulated nanoseconds to seconds:
The only leap-second specific thing in it is the function second_overflow() called in the line linked above, it's implementation is linked below. seconds_overflow() checks if a flag updated by NTP which means "there will be a (positive or negative) leap second at the end of today" (bits in time_state) is active, and if that's the case the last second will be repeated, or skipped.
So, computationally, keeping the general complexity of timekeeping in mind, leap second processing is completely insignificant, as evident by the comparatively tiny second_overflow() function.
Here's the function in the Linux-Kernel that's counting the seconds. It's actually not specified if this function is called exactly every second, or more often, or less often. It just overflows accumulated nanoseconds to seconds:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux....
The only leap-second specific thing in it is the function second_overflow() called in the line linked above, it's implementation is linked below. seconds_overflow() checks if a flag updated by NTP which means "there will be a (positive or negative) leap second at the end of today" (bits in time_state) is active, and if that's the case the last second will be repeated, or skipped.
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux....
So, computationally, keeping the general complexity of timekeeping in mind, leap second processing is completely insignificant, as evident by the comparatively tiny second_overflow() function.