Date: Mon, 24 Jun 2002 21:43:13 -0500 From: Alan Cox <alc@cs.rice.edu> To: Peter Wemm <peter@wemm.org> Cc: Ian Dowse <iedowse@FreeBSD.org>, 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: <20020625024313.GI11391@cs.rice.edu> In-Reply-To: <20020624022343.3FDDB380E@overcee.wemm.org> References: <200206232157.g5NLvKF31769@freefall.freebsd.org> <20020624022343.3FDDB380E@overcee.wemm.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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. > ... Since Ian is following up on some of the other issues related to this change, I ran a test using a script that performs three rounds of "make clean", "make depend", and "make" on a kernel source tree. On each round, the script times the final "make". The only variable in this test was the size of vm_pindex_t. In short, there was virtually no difference: /tmp/vm_pindex-32: 1135.28 real 1031.08 user 110.99 sys /tmp/vm_pindex-32: 1134.02 real 1029.93 user 111.84 sys /tmp/vm_pindex-32: 1137.11 real 1030.32 user 111.08 sys /tmp/vm_pindex-64: 1134.62 real 1031.13 user 110.43 sys /tmp/vm_pindex-64: 1133.16 real 1030.69 user 110.30 sys /tmp/vm_pindex-64: 1132.50 real 1029.74 user 111.01 sys Do you have any idea what sorts of tests John was running? Alan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020625024313.GI11391>