Messages in this thread | | | Date | Sun, 7 Nov 1999 22:42:54 +0100 (CET) | From | Robert de Vries <> | Subject | Re: gettimeofday being faster than getpid? |
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On Tue, 2 Nov 1999, Pavel Machek wrote:
> Hi! > > I did some tests, and when I replace getuid() or getpid() with > gettimeofday(), it actually gets faster. > > getuid takes 14usec on my machine. > gettimeofday takes 4usec on my machine. > > I think that is pretty strange. > Pavel > > #include <sys/time.h> > #include <unistd.h> > > void main(void) > { > struct timeval tv1, tv2, tv3; > > gettimeofday(&tv1, 0); > getuid(); <--- here > gettimeofday(&tv2, 0); > > printf("Time1: %d:%d\n", tv1.tv_sec, tv1.tv_usec); > printf("Time2: %d:%d\n", tv2.tv_sec, tv2.tv_usec); > }
Just add one getuid() before the first gettimeofday() and the strangeness takes another form. The difference disappears. I'm afraid you are measuring your cache performance I guess.
Robert
-- Robert de Vries rhdv@rhdv.cistron.nl
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