From: pedersen@philmtl.philips.ca (Paul Pedersen)
Subject: Re: Inheritance & limited private types
Date: 27 Oct 89 15:44:28 GMT [thread overview]
Message-ID: <800@philmtl.philips.ca> (raw)
In-Reply-To: 31018@news.Think.COM
In article <31018@news.Think.COM> barmar@kulla (Barry Margolin) writes:
>
>Making a program efficient without a profiler is like making a program work
>without a debugger. Sure, you can manually sprinkle your code with print
>statements and timing statements, but it's not an efficient way to do it.
>
I spent some time last year trying to profile a large UNIX-based system
running on a 386. Turned out to be a waste of time since profiling is
driven by UNIX clock-ticks which, at least on our system, is 100t/sec.
I found that the software (under test) could execute up to 30 function
calls between ticks, so most functions never got hit by the interupt, and
all time-spent-in-function's were meaningless.
Speeding up the interrupt frequency is apparently not a good idea since
most time will then be spent in context-switch's.
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) :-)
Paul Pedersen (pedersen@philmtl)
next prev parent reply other threads:[~1989-10-27 15:44 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
1989-10-16 13:57 Does Ada really need MULTIPLE inheritance? "Norman H. Cohen"
1989-10-17 17:23 ` David A Eichmann,316K
1989-10-17 20:49 ` David Chase
1989-10-21 19:39 ` Inheritance & limited private types William Thomas Wolfe, 2847
1989-10-22 7:00 ` Vinod Grover
1989-10-22 18:03 ` Inheritance & limited private t stt
1989-10-22 20:22 ` Inheritance & limited private types Barry Margolin
1989-10-23 0:39 ` Ted Dunning
1989-10-27 15:44 ` Paul Pedersen [this message]
1989-10-27 17:50 ` Robert Firth
1989-10-27 22:32 ` Profiling (was Re: Inheritance & limited private types) Barry Margolin
1989-10-27 0:04 ` Inheritance & limited private types Dick Karpinski
1989-10-30 17:12 ` Does Ada really need MULTIPLE inheritance? Paul Baker
1989-10-19 2:27 ` William Thomas Wolfe, 2847
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox