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From Cliff Skolnick <cl...@steam.com>
Subject Re: Patch to slow down children's deaths (fwd)
Date Wed, 08 Jan 1997 01:58:20 GMT

On Tue, 7 Jan 1997, Jim Jagielski wrote:
> > Will we need this in 2.0 if we're threading?
> > 
> 
> Not likely... additional child processes will be semi-rare

for many OS each process is limited to only one kernel level thread.  This
means only one thread can do any system call like a read() at a time, and
the others will patiently block.  For these OSs there will still need to
be many processes to balance the I/O load.  This is the case with
pthreads() for bsd systems last time I looked.

For some OSs like solaris, you can vary the number of kernel threads bound
to a user process, then the number of user process level threads and how
they are bound to those kernel threads.

If threading is not done carefully, it is very easy to introduce I/O 
bottlenecks.

--
Cliff Skolnick, Technical Consultant
Steam Tunnel Operations
cliff@steam.com, 415.297.5938
http://www.steam.com/



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