Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262213AbUCHJI4 (ORCPT ); Mon, 8 Mar 2004 04:08:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262298AbUCHJI4 (ORCPT ); Mon, 8 Mar 2004 04:08:56 -0500 Received: from [139.30.44.16] ([139.30.44.16]:12725 "EHLO gockel.physik3.uni-rostock.de") by vger.kernel.org with ESMTP id S262213AbUCHJIx (ORCPT ); Mon, 8 Mar 2004 04:08:53 -0500 Date: Mon, 8 Mar 2004 10:08:48 +0100 (CET) From: Tim Schmielau To: Arthur Corliss cc: Linux Kernel Mailing List Subject: Re: [PATCH] Re: 2.6.x BSD Process Accounting w/High UID In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2683 Lines: 62 [Cc: trimmed] On Sun, 7 Mar 2004, Arthur Corliss wrote: > On Sun, 7 Mar 2004, Tim Schmielau wrote: > > > But the current tools are only broken for the few people using high UIDs > > (and generally on 64 bit archs, but that's a different story). > > This is broken on x86 as well. I guess I still have to question the logic of > logging bad data, even if you think the data is infrequent at best. Seems like I didn't get your point. What is broken on x86 other than high UIDs? > > We shouldn't require people to recompile their userspace tools in the > > middle of a stable kernel series. (OK, 2.6 has just started, but we don't > > want to offend people upgrading from 2.4, either.) > > I can understand this argument, and I would certainly agree for things that > are commonly used. But given the state of the BSD accounting tools (a package > that hasn't had a public update since 1998, and which has non-high uid broken > bits in it as well) I would hazard a guess that the impacted users is going to > be minimal, at best. In which way are the BSD accounting tools broken? I'm unfamiliar with them, but this might indeed allow us to estimate the user base. > > How about the patch below? It requires a change to userspace tools if you > > want to use high uids, but it dosn't break binary compatibility. It even > > allows userspace to check whether high UIDs are supported, and allows > > future incompatible format changes to be detected. > > I like it, and the addition of ac_version is a great idea. I might alter the > comment about 64-bit machines in acct.c, though. 32-bit UIDs affects 32-bit > machines as well. The chunk with the 64-bit comment actually is independent of the high UID problem. It's there to prevent logging of wromng data on 64-bit arches, and is completely optimized away by the compiler on 32 bit ones. I could as well separate it into a different patch. I'll do a new version of the patch anyways, as I missed to change another comment. > > Well, they are not totally meaningless since we clip at the maximum > > representable value instead of wrapping around. > > :-P I don't look at this any different than the byte-clipping we're doing with > UIDs. If we're logging data that's wrong, then you can't do accurate > accounting, period. Yes, but how often do your users use more that 49 days of cputime? I'll wait a bit to see whether my other posting generates any feedback. Tim - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/