From owner-cvs-src@FreeBSD.ORG Wed Sep 28 17:24:00 2005 Return-Path: X-Original-To: cvs-src@FreeBSD.org Delivered-To: cvs-src@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9109616A420; Wed, 28 Sep 2005 17:24:00 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from mv.twc.weather.com (mv.twc.weather.com [65.212.71.225]) by mx1.FreeBSD.org (Postfix) with ESMTP id C124B43D55; Wed, 28 Sep 2005 17:23:58 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from [10.50.41.233] (Not Verified[10.50.41.233]) by mv.twc.weather.com with NetIQ MailMarshal (v6, 0, 3, 8) id ; Wed, 28 Sep 2005 13:39:56 -0400 From: John Baldwin To: Jeremie Le Hen Date: Wed, 28 Sep 2005 13:07:11 -0400 User-Agent: KMail/1.8 References: <200509271809.j8RI9gCO020672@repoman.freebsd.org> <20050928091638.GB2151@obiwan.tataz.chchile.org> In-Reply-To: <20050928091638.GB2151@obiwan.tataz.chchile.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200509281307.13026.jhb@FreeBSD.org> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern kern_prot.c vfs_export.c src/sys/nfsserver nfs_srvsock.c nfs_srvsubs.c src/sys/sys ucred.h src/sys/ufs/ufs ufs_vnops.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Sep 2005 17:24:00 -0000 On Wednesday 28 September 2005 05:16 am, Jeremie Le Hen wrote: > Hi John, > > > jhb 2005-09-27 18:09:42 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/kern kern_prot.c vfs_export.c > > sys/nfsserver nfs_srvsock.c nfs_srvsubs.c > > sys/sys ucred.h > > sys/ufs/ufs ufs_vnops.c > > Log: > > Use the refcount API to manage the reference count for user credentials > > rather than using pool mutexes. > > Regarding your great job on atomic operations and the modification you > made on process argument and process limit structures as well as > user credentials, I wonder if you managed to get some figures > illustrating the improvement. No, I didn't run any before/after benchmarks, just stability tests to make sure I didn't break anything. I'm pretty sure 2 atomic operations aren't cheaper than just 1 though. However, on some archs (ppc and ia64 currently) there might be a penalty in the edge case where the atomic_cmpset loop races and has to do more than one atomic_cmpset. However, in that case it would have had to contest on the mutex anyways, so even then I still think it would be a win. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org