DragonFly BSD
DragonFly kernel List (threaded) for 2004-02
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Re: lkwt in DragonFly

From: Dan Melomedman <dan@xxxxxxxxxxx>
Date: Tue, 10 Feb 2004 15:29:28 -0500

Miguel Mendez wrote:
> Jeroen Ruigrok/asmodai wrote:
> >I prefer to go with a hybrid method.  1:1 doesn't work.
> Could you elaborate on that? I agree that the prefered implementation is
> something KSE/SA alike, but Solaris is moving to 1:1 after years of 
> trying to make N:M work properly. The main problem I see with 1:1 

I hear that the main problem with Slowaris is slow fork()/exec(). So
Slowaris software ends-up using threads in _place_ of processes. Furthermore,
pthreads are a very generic threads library which is, IMHO often used
where it shouldn't, and also incorrectly. For instance many people
blindly assume that creating a bazillion threads is okay because they
are somehow magically faster than processes, but don't even bother profiling.
If performance matters, than why are they creating more threads than they
have CPUs in the first place? Also often people choose pthreads over
some more convenient thread library, and inflict mutexes, race
conditions and other problems on themselves.

There should not be anything inherently slow about creating a process on
modern OSes. If an OS has a slow fork(), that's OS designers' problem,
not userland programmers'.

Anybody practicing the fine art of composing music, no matter how
cynical or greedy or scared, still cant help serving all humanity.
Music makes practically everybody fonder of life than he or she
would be without it.
  --Kurt Vonnegut

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