Re: Inheritance & limited private types

[firth@sei.cmu.edu (Robert Firth)]

In article <800@philmtl.philips.ca> pedersen@philmtl.philips.ca (Paul Pedersen) writes:

>The conclusion I came to was that it is not possible to do profiling 
>using UNIX on a fast processor, short of using a logic analyzer and a
>lot of interpreting software (far from sure that this is even feasable).
>
>I would be *very* interested in hearing from anybody who has solved this
>problem (I gave up) :-)

Gee, I implemented profiling on this Unix machine in an afternoon.
Admittedly, I was helped by the existence of a system call 'profil',
which does all the real work.

The purpose of profiling is to find out where the program is spending
a lot of its time.  Now, the profiling command samples the program
counter 100 times a second, so in a one-minute run that is 6000
samples.  Any subprogram body that consumes more than 1% of the mill
will therefore generate on average more than 60 hits, which is surely
a meaningful number.

If no program run ever takes more than a minute, few Unix users will
care about having it tuned.  And if a given function uses less than
1% of the mill, you don't care about tuning it.