Re: gettimeofday() system call timing curiosity

Alan Cox (alan@lxorguk.ukuu.org.uk)
Fri, 8 Mar 2002 19:19:55 +0000 (GMT)

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> The following program clearly shows that Linux will not return the
> same gettimeofday values twice in succession. Since it provably takes
> less than 1 microsecond to make a system call on a modern machine,

We don't wait. Your computer just sucks 8)

More seriously even on a processor with a TSC we have to take a lock and
do several computations.

Alan
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