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From Justin Erenkrantz <>
Subject Re: OSDLab projectL Accept() locking on large (6+ CPU) boxes
Date Tue, 24 Jul 2001 18:54:37 GMT
On Tue, Jul 24, 2001 at 11:32:25AM -0700, Brian Pane wrote:
> Are you able to observe this effect experimentally too?  E.g., if
> you run the threaded MPM on Solaris, does it use just one LWP per
> process?

Not with threaded MPM because it uses blocking system calls which allow
Solaris's scheduler to jump in and rebalance.  Initially, it'll be
one LWP, but after some load hits, it should spawn multiple LWPs and
rebalance the threads accordingly.

However, try testthread on Solaris (with an MP box) and it'll execute 
all of the threads in serial rather than parallel.  This is what drove
me crazy last night - forcing me to comb through the manpages until I
hit upon the pthread_setconcurrency call. 

By leveraging the pthread_setconcurrency call, the threads are balanced
across LWPs immediately rather than waiting for each thread to hit a
blocking system call or yield.  -- justin

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