Natterings about history files

[Nicholas Geovanis]

On 8 Mar 2001, bill davidsen wrote:

> | Sure, it should be possible for people to try stuff out.  I think you're
> | fooling yourself if you think that steady-state expiration is going to buy
> | you any scaling over nightly expire given the same basic underlying
> | structures, though.  (In other words, different structures will give you
> | better performance, but those performance gains would be realized by the
> | same structure using a nightly expire too.)
> 
>   I suspect things have to change anyway, the size of files is getting
> near the per-process address space of many systems, and at some point
> soon we will lose the ability to mmap() on those systems. I have to do
> serious hacks to AIX executables to get more than the default 256MB
> process data space, and I can only have 2GB with the fix. This is
> address space, not files size, different ugliness.

You should only have to compile with "-bmaxdata", right? (OK, I'm 
assuming that you're using IBM's compiler) And the 2GB limit is only for
the data segment; stack and program text are in separate segments and
don't count against it.

If you're not using IBM's compiler, yes, you have to do the one-line shell
script hack to enable maxdata in the executable. But frankly, if you're
really trying to optimise the code for AIX, you want the IBM compiler.
Honest. 

> bill davidsen <davidsen at tmr.com>

* Nick Geovanis
| IT Computing Svcs
| Northwestern Univ
| n-geovanis at nwu.edu
+------------------->