Subject: Re: SMP re-entrancy in kernel drivers/"bottom half?"
To: Allen Briggs <briggs@wasabisystems.com>
From: Jonathan Stone <jonathan@dsg.stanford.edu>
List: tech-kern
Date: 02/23/2005 12:16:38
In message <20050223195822.GN388@canolog.ninthwonder.com>,
Allen Briggs writes:

>I think there has been some discussion of this recently on a couple
>of different NetBSD mailing lists.  Perhaps netbsd-advocacy@ and
>tech-perform@ ?

Hm. Indeed, the tech-perform@ archives do have discussion.  Turns out
these same benchmark results triggered Chuck's finishing up read()
loanout for regular files (so he can do write-loanout, which will help
overwrite (a` la bonnie rewrite?), which is expected to help the
10M-row tests where NetBSD does so poorly.

I also notice PTHREAD_CONCURRENCY being changed from the old default
of 1 to the number of CPUs found at boot, which was expected to
dramatically improve the two-CPU tests. (Though I dont see why that
would make us strictly worse with two CPUs versus one CPU?)