Subject: Re: Alpha MP goes multi-user, code committed to NetBSD-current
To: None <firstname.lastname@example.org>
From: Toru Nishimura <email@example.com>
Date: 04/22/2001 14:14:02
> Folks, today I got multiprocessor Alpha kernels to go multi-user,
> running both user and kernel code on multiple processors. It even
> seems to be pretty stable (did a kernel build, doing a full userland
> build right now, and will build an Alpha binary snapshot with the
> MP kernel later).
It's G-R-E-A-T. While waiting for cvs update completed for my own
copy, I would ask a small/quick question.
> There's definitely more work to do. In particular, TLB invalidation
> traffic has to be managed better. Take a look at the frequence of
> interprocessor interrupts:
> frau-farbissina:thorpej 23$ vmstat -i
> interrupt total rate
> cpu0 clock 3063914 1204
> cpu0 shootdown ipi 3126178 1228
> cpu1 clock 3049191 1198
> cpu1 shootdown ipi 2295031 902
> Note that TLB shootdown requests are about as frequent as the clock
> interrupt :-/ Anyway, future work -- at least it runs :-)
How can this phenomenon happen? It's counter-intuitive, and rather
magic the kernel is useful after all.
And about pmap_emulate_reference(). It's also a trouble source for my
MIPS pmap so far. It seems necessary to pay more thought and work for
all possible cases around it.
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