file seek is slow

[sjdevnull at yahoo.com]

On Mar 10, 6:01 pm, Neil Hodgson <nyamatongwe+thun... at gmail.com>
wrote:
> Metalone:
>
> > As it turns out each call is only
> > 646 nanoseconds slower than 'C'.
> > However, that is still 80% of the time to perform a file seek,
> > which I would think is a relatively slow operation compared to just
> > making a system call.
>
>    A seek may not be doing much beyond setting a current offset value.
> It is likely that fseek(f1, 0, SEEK_SET) isn't even doing a system call.

Exactly.  If I replace both calls to fseek with gettimeofday (aka
time.time() on my platform in python) I get fairly close results:
$ ./testseek
4.120
$ python2.5 testseek.py
4.170
$ ./testseek
4.080
$ python2.5 testseek.py
4.130


FWIW, my results with fseek aren't as bad as those of the OP.  This is
python2.5 on a 2.6.9 Linux OS, with psyco:
$ ./testseek
0.560
$ python2.5 testseek.py
0.750
$ ./testseek
0.570
$ python2.5 testseek.py
0.760