On Tue, 17 Dec 2002, H. Peter Anvin wrote:
>
> Let's see... it works fine on UP and on *most* SMP, and on the ones
> where it doesn't work you just fill in a system call into the vsyscall
> slot. It just means that gettimeofday() needs a different vsyscall slot.
The thing is, gettimeofday() isn't _that_ special. It's just not worth a
vsyscall of it's own, I feel. Where do you stop? Do we do getpid() too?
Just because we can?
This is especially true since the people who _really_ might care about
gettimeofday() are exactly the people who wouldn't be able to use the fast
user-space-only version.
How much do you think gettimeofday() really matters on a desktop? Sure, X
apps do gettimeofday() calls, but they do a whole lot more of _other_
calls, and gettimeofday() is really far far down in the noise for them.
The people who really call for gettimeofday() as a performance thing seem
to be database people who want it as a timestamp. But those are the same
people who also want NUMA machines which don't necessarily have
synchronized clocks.
Linus
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This archive was generated by hypermail 2b29 : Mon Dec 23 2002 - 22:00:17 EST