From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759654Ab0JZN6Y (ORCPT ); Tue, 26 Oct 2010 09:58:24 -0400 Received: from Mycroft.westnet.com ([216.187.52.7]:47872 "EHLO mycroft.westnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757937Ab0JZN6X (ORCPT ); Tue, 26 Oct 2010 09:58:23 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <19654.56921.305451.776696@quad.stoffel.home> Date: Tue, 26 Oct 2010 09:57:45 -0400 From: "John Stoffel" To: Eric Paris Cc: "H. Peter Anvin" , John Stoffel , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, zohar@us.ibm.com, warthog9@kernel.org, david@fromorbit.com, jmorris@namei.org, kyle@mcmartin.ca, akpm@linux-foundation.org, torvalds@linux-foundation.org, mingo@elte.hu, viro@zeniv.linux.org.uk Subject: Re: [PATCH 06/11] IMA: use i_writecount rather than a private counter In-Reply-To: <1288045749.2655.49.camel@localhost.localdomain> References: <20101025184118.20504.24290.stgit@paris.rdu.redhat.com> <20101025184152.20504.94048.stgit@paris.rdu.redhat.com> <19653.55831.692904.538148@quad.stoffel.home> <1288043557.2655.34.camel@localhost.localdomain> <4CC603E3.3070405@zytor.com> <1288045749.2655.49.camel@localhost.localdomain> X-Mailer: VM 8.1.1 under 23.2.1 (x86_64-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Eric" == Eric Paris writes: Eric> On Mon, 2010-10-25 at 15:25 -0700, H. Peter Anvin wrote: >> On 10/25/2010 02:52 PM, Eric Paris wrote: >> > On Mon, 2010-10-25 at 15:27 -0400, John Stoffel wrote: >> > >> >> The problems with kernel.org is a perfect exmaple of how an annocuous >> >> feature like this, can kill a system's performance. >> > >> > You admit that you don't know what you are talking about and then state >> > that this kills systems performance. Interesting conclusion. >> > >> > I'm not going to try to refute you point by point but will instead paint >> > a broad picture. I see 3 possible states: >> > 1) Configured out - 0 overhead. period. >> > 2) Configured in but default disabled >> > 3) Configured in and enabled by admin intervention >> > >> > I have (I think) pretty clearly discussed the overhead and the changes >> > made in case #2. We expand struct inode by 4 bytes, we increment and >> > decrement those 4 bytes on open/close() and we use a new inode->i_flags. >> > >> >> Case #2 is the bad one, as long as distros are likely to compile it in. Eric> Agreed. And that's the case this whole patch series is addressing. It Eric> makes it (literally not figuratively) hundreds of times better than it Eric> is today :) And just to chime in, I really appreciate your hard work on this cleanup! John