Re: linux scheduler limitations?

["J . A . Magallon" <jamagallon@able.es>]

On 03.30 Fabio Riccardi wrote:
> 
> Despite of all apparences this method performs beautifully on Linux, pthreads
> are
> actually slower in many cases, since you will incur some additional overhead
> due
> to thread synchronization and scheduling.
>

It all depends on your app, as every parallel algorithm. In a web-ftp-whatever
server, you do not need any synchro. You can start threads in free run and
let them die alone.

> The problem is that beyond a certain number of processes the scheduler just
> goes
> bananas, or so it seems to me.
> 
> Since Linux threads are mapped on processes, I don't think that (p)threads
> woud
> help in any way, unless it is the VM context switch overhead that is playing a
> role here, which I wouldn't think is the case.
> 

You said, 'mapped'.
AFAIK, that is the advantage, you can avoid the VM switch by sharing memory.

-- 
J.A. Magallon                                          #  Let the source
mailto:jamagallon@able.es                              #  be with you, Luke... 

Linux werewolf 2.4.2-ac28 #1 SMP Thu Mar 29 16:41:17 CEST 2001 i686