Re: Linux 2.6 nanosecond time stamp weirdness breaks GCC build

[James H. Cloos Jr.]

>>>>> "Jamie" == Jamie Lokier <jamie@xxxxxxxxxxxxx> writes:

Jamie> When re-reading an inode, rounding the time up is done by
Jamie> setting the tv_nsec field to 999999999.

Jamie> If the on-disk timestamp is "now", i.e. the current second if
Jamie> it's a 1-second resolution, then we can avoid setting the
Jamie> timestamp to a future time by setting the tv_nsec field to the
Jamie> current wall time's nanosecond value.  There is no need to
Jamie> round the time up any more than that.

Given how much time it will take to compare the file's timestamp to
current before choosing 999999999 or now for the tv_nsec field, is
it a reasonable shortcut to just always use now's nsec value?

Obviously it is not *that* many cycles to do the compare, but we are
talking about a nanoseconds field, and the current tv_sec could
increment during the compare....

-JimC

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