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Date:      Sun, 23 Jun 2002 19:23:43 -0700
From:      Peter Wemm <peter@wemm.org>
To:        Ian Dowse <iedowse@FreeBSD.org>
Cc:        cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/powerpc/include types.h src/sys/arm/include types.h src/sys/i386/include types.h 
Message-ID:  <20020624022343.3FDDB380E@overcee.wemm.org>
In-Reply-To: <200206232157.g5NLvKF31769@freefall.freebsd.org> 

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Ian Dowse wrote:
> iedowse     2002/06/23 14:57:19 PDT
> 
>   Modified files:
>     sys/powerpc/include  types.h 
>     sys/arm/include      types.h 
>     sys/i386/include     types.h 
>   Log:
>   Make vm_pindex_t 64-bit on all platforms. This is necessary to avoid
>   overflows with the large file sizes that UFS2 permits.

Ouch, is this really necessary?  The whole index::offset thing was
explicitly to avoid using 64 bit arithmetic here due to the performance
hit.    Dyson posted some numbers somewhere in the distant past, they can
probably be found on the archives.

If this really is necessary, then we may as well strip out the pindex stuff
entirely and just use 64 bit byte offsets instead of
"64bit pindex::32bit offset".  ie: why carry a 96 bit synthetic value when
we only need a 64 bit value?

Cheers,
-Peter
--
Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com
"All of this is for nothing if we don't go to the stars" - JMS/B5


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