From owner-cvs-all Sun Jun 23 19:46:22 2002 Delivered-To: cvs-all@freebsd.org Received: from cs.rice.edu (cs.rice.edu [128.42.1.30]) by hub.freebsd.org (Postfix) with ESMTP id 4B48037B400; Sun, 23 Jun 2002 19:46:18 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by cs.rice.edu (Postfix) with ESMTP id A0F584A9CD; Sun, 23 Jun 2002 21:46:17 -0500 (CDT) Received: by cs.rice.edu (Postfix, from userid 19572) id 88F894A9CC; Sun, 23 Jun 2002 21:46:16 -0500 (CDT) Date: Sun, 23 Jun 2002 21:46:16 -0500 From: Alan Cox To: Peter Wemm Cc: Ian Dowse , 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: <20020624024616.GF11391@cs.rice.edu> References: <200206232157.g5NLvKF31769@freefall.freebsd.org> <20020624022343.3FDDB380E@overcee.wemm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020624022343.3FDDB380E@overcee.wemm.org> User-Agent: Mutt/1.3.28i X-Virus-Scanned: by AMaViS snapshot-20010714 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, Jun 23, 2002 at 07:23:43PM -0700, Peter Wemm wrote: > 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? I agree with this observation. I've been discussing precisely what you describe with Ian. Alan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message