From owner-freebsd-hackers Sun Dec 15 1:12:31 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 26E5337B401 for ; Sun, 15 Dec 2002 01:12:30 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3376A43EF1 for ; Sun, 15 Dec 2002 01:12:29 -0800 (PST) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id gBF9CEJe049291; Sun, 15 Dec 2002 10:12:23 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Nate Lawson Cc: Michael Ranner , freebsd-hackers@FreeBSD.ORG Subject: Re: setattr() syscall as proposed by phk From: phk@FreeBSD.ORG In-Reply-To: Your message of "Sun, 15 Dec 2002 00:50:35 PST." Date: Sun, 15 Dec 2002 10:12:14 +0100 Message-ID: <49290.1039943534@critter.freebsd.dk> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message , Nate Lawson wri tes: >On Sat, 14 Dec 2002, Michael Ranner wrote: >> Hi there! >> >> I have implemented the setattr(), lsetattr() and fsetattr() syscalls for >> 4.7 and 5.0. You can review my code on http://www.ranner.jawa.at/freebsd.php. >> >> Comments and suggestions are welcome. > >I don't mean to be rude but I doubt the utility of this whole >plan. dump/restore are done on disk devices which are at least an order >of magnitude slower than a syscall boundary crossing. Going from 4 >syscalls to 1 can't make a bit of difference in restore(8) performance. You are wrong about restore: restore is done on a mounted filesystem. >So why is this faster? Something is likely slowing namei() down. Because 1 syscall and 2 namei calls are faster than 4 syscalls and four namei calls. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message