From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760381AbZBMSFz (ORCPT ); Fri, 13 Feb 2009 13:05:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752634AbZBMSFp (ORCPT ); Fri, 13 Feb 2009 13:05:45 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:50034 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182AbZBMSFp (ORCPT ); Fri, 13 Feb 2009 13:05:45 -0500 Date: Fri, 13 Feb 2009 19:05:13 +0100 From: Ingo Molnar To: Mathieu Desnoyers , Steven Rostedt Cc: Peter Zijlstra , Nick Piggin , akpm , linux-kernel Subject: Re: irq-disabled vs vmap vs text_poke Message-ID: <20090213180513.GC18581@elte.hu> 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> <20090213144346.GA857@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090213144346.GA857@Krystal> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mathieu Desnoyers wrote: > * 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 it doesnt always trigger. It triggers on a box that also generates a lot of NMIs - maybe there's a connection? Ingo