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From: Bruce Evans <bde@zeta.org.au>
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To: Julian Elischer <julian@elischer.org>
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cc: FreeBSD current users <current@freebsd.org>
Subject: Re: small scheduler hack/patch
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On Thu, 10 Jul 2003, Julian Elischer wrote:

> I have a small "proof of concept" scheduler hack at:
> http://www.freebsd.org/~julian/it.diff
> ...
> It's only implemented for SMP/i386 as the code to halt the cpu is only
> present (from my quick view) in x86 and it doesn't make sense in UP..

ipi_selected() is essentially MI although it is declared in
<machine/smp.h> and takes MD arg types, since it is used in subr_smp.c
and subr_smp.c is MI by definition.  Its second arg is u_int64_t on
alphas, int on ia64's, and u_int on other arches.  This isn't a problem
since the arg is always a #define'd value like IPI_AST and these values
have MD definitions.  Its first arg has type u_int64_t on ia64's and
u_int on other arches.  This is bogus for ia64's since subr_smp.c uses
u_int for all bitmaps of CPUs, so systems with more than 32 CPUs cannot
actually work.

Bruce