shell, perl, performance, parallelism, profiling, etc. (was: Upgrade guidance)

[Kevin D. Clark]

Ben Scott writes:

>   Consider: If the RPM database is in cache, then the
> "package-cleanup" utility is going to mainly be reading data from
> already cached pages (memory mapped file I/O).  In the Perl script,
> everything is serialized.  But in the bash script, both
> package-cleanup invocations can -- I'm guessing -- run concurrently.
> One on each core.  I think the "package-cleanup" runs are the
> slowest thing by far in this process, so if they can both run at the
> same time, that might do so well as to cut wall clock time *in
> half*.  That might well make-up for otherwise slow tasks.

The thing that you are dancing around is called Amdahl's Law, BTW.

Regards,

--kevin
-- 
Let me put it to you this way: computers are my business.
--Andrew Hume