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Date: Wed, 30 Apr 1997 16:11:52 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199704300611.QAA07968@godzilla.zeta.org.au>
To: cvs-all@FreeBSD.org, CVS-committers@FreeBSD.org, cvs-sys@FreeBSD.org,
        peter@freefall.FreeBSD.ORG
Subject: Re: cvs commit:  src/sys/i386/include spl.h src/sys/i386/isa vector.s
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>  Modified:    sys/i386/include  spl.h
>               sys/i386/isa  vector.s
>  Log:
>  Use a common numbering of the tty and net software interrupt levels
>  between the SMP and non-SMP case.  It simplifies the #ifdef's, since
>  NHWI changes (at least for the moment) when APIC's are involved.

This is a pessimization for the non-SMP case.  It takes 3*N cycles on
386's and N cycles on [4-5]86's for the `bsfl' instruction to scan for
the bits when they are N bits higher (N = 12 here).

Bruce