From owner-freebsd-current  Fri Jan 29 10:51:08 1999
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To: dick@tar.com
CC: dillon@apollo.backplane.com, current@FreeBSD.ORG
In-reply-to: <19990129092202.T421@tar.com> (dick@tar.com)
Subject: Re: Locked at 100% User CPU
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   >     This code looks pretty bad, all right.  It looks like it is O(N^2)
   >     in PS_SELECT_WAIT(), especially if descriptors get randomly strewn
   >     amoungst the threads.  It also looks like it is regenerating the FDS masks
   >     on each call completely from scratch.  It also looks like it is
   >     scanning the entire thread list - both waiting and running threads,
   >     to prioritize the next thread to run and then scanning it again
   >     to select the thread priority, then scanning the whole list yet
   >     again to find the one it wants to run.
   > 
   >     This is massively unscaleable code.  Is anyone actively working on
   >     it?

I think if I knew exactly what this code was trying to do, I could
rewrite it. However, it is quite complex.

I'm tempted to look into Richard's stuff. However, this pthread stuff
is quite stable. (at least with a few minor tweaks). If this part
scaled a WHOLE LOT better, we'd probably be okay.

Richard: How "checked" in is your stuff? What does one have to do to
start using it? Kernel mods?

-Rob

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