From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761197AbZBMOoP (ORCPT ); Fri, 13 Feb 2009 09:44:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754480AbZBMOn7 (ORCPT ); Fri, 13 Feb 2009 09:43:59 -0500 Received: from tomts36.bellnexxia.net ([209.226.175.93]:56969 "EHLO tomts36-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753038AbZBMOn6 (ORCPT ); Fri, 13 Feb 2009 09:43:58 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ah0FABQRlUlMQWt2/2dsb2JhbACBbtEPhBgG Date: Fri, 13 Feb 2009 09:43:46 -0500 From: Mathieu Desnoyers To: Peter Zijlstra Cc: Ingo Molnar , Nick Piggin , akpm , linux-kernel Subject: Re: irq-disabled vs vmap vs text_poke Message-ID: <20090213144346.GA857@Krystal> References: <1234529407.6519.28.camel@twins> <20090213125505.GE18462@wotan.suse.de> <1234530138.6519.38.camel@twins> <20090213130450.GB9346@elte.hu> <20090213142521.GB31922@Krystal> <1234535626.6519.113.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <1234535626.6519.113.camel@twins> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 09:42:12 up 43 days, 14:40, 4 users, load average: 0.40, 0.38, 0.30 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra (peterz@infradead.org) wrote: > On Fri, 2009-02-13 at 09:25 -0500, Mathieu Desnoyers wrote: > > * Ingo Molnar (mingo@elte.hu) wrote: > > > > > > * Peter Zijlstra wrote: > > > > > > > > I think I got a mostly working patch cobbled together sitting here > > > > > somewhere. I was waiting for some _really_ good use case before spending > > > > > more time on it. I would prefer if at all possible to do vmap operations > > > > > in sleepable, process context. > > > > > > > > Agreed, I think we want to fix text_poke() and make the vmap/vunmap() > > > > ops yell louder at violations of these rules. > > > > > > > > I'm just totally clueless wrt text_poke() hence this email ;-) > > > > > > also, this started triggering yesterday for the first time - and never > > > saw it before. Has some commit caused this side-effect? > > > > > > It triggers during kprobes self-test - has that been improved recently? > > > > > > > When is this self-test run ? If it's at early boot while still in UP > > with interrupts off, kprobes should probably use text_poke_early() > > rather than text_poke(). > > Looking at the dmesg it looks to be post smp-init, so its late init > calls. > > I think its the do_initcalls() from do_basic_setup(). So the machine > should be mostly up and running. Here with 2.6.29-rc4 (commit 8e4921515c1a379539607eb443d51c30f4f7f338). I don't seem to get any warning with a might_sleep() in text_poke. Kprobe smoke test started Kprobe smoke test passed successfully Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68