In message: <Pine.LNX.4.64.0701070304400.11581_at_hermes-1.csi.cam.ac.uk>
Tony Finch <dot_at_dotat.at> writes:
: On Sat, 6 Jan 2007, Ashley Yakeley wrote:
: >
: > Presumably it only needs to know the next leap-second to do this, not
: > the whole known table?
:
: Kernels sometimes need to deal with historical timestamps (principally
: from the filesystem) so it'll need a full table to be able to convert
: between POSIX time and atomic time for compatibility purposes.
Most filesystems store time as UTC anyway...
And that's one reason that kernels do a lot of timestamp operations:
whenever a file is touched, one has to update the time it was last
touched. Then, when the file is statted, that time must be returned.
That makes it very hard to do all in libc because of different boot
times or nfs, etc. While one could do the degenerate case of
gettimeofday in libc, these other cases are much harder.
Warner
Received on Sat Jan 06 2007 - 22:27:48 PST