Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752157AbYHKMN1 (ORCPT ); Mon, 11 Aug 2008 08:13:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750855AbYHKMNT (ORCPT ); Mon, 11 Aug 2008 08:13:19 -0400 Received: from one.firstfloor.org ([213.235.205.2]:35655 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781AbYHKMNS (ORCPT ); Mon, 11 Aug 2008 08:13:18 -0400 Date: Mon, 11 Aug 2008 14:14:22 +0200 From: Andi Kleen To: Ingo Molnar Cc: Peter Zijlstra , Andi Kleen , Andrew Morton , torvalds@linux-foundation.org, tglx@linutronix.de, marcin.slusarz@gmail.com, linux-kernel@vger.kernel.org, davem@davemloft.net, rostedt@goodmis.org, paulmck@linux.vnet.ibm.com Subject: Re: [PATCH] printk: robustify printk Message-ID: <20080811121422.GQ9038@one.firstfloor.org> References: <1218217257.29098.2.camel@lappy.programming.kicks-ass.net> <1218219269.29098.5.camel@lappy.programming.kicks-ass.net> <20080808121428.646a8b3c.akpm@linux-foundation.org> <1218223269.29098.12.camel@lappy.programming.kicks-ass.net> <1218224829.29098.19.camel@lappy.programming.kicks-ass.net> <20080811104526.GA15186@elte.hu> <87zlnj24qc.fsf@basil.nowhere.org> <1218453726.10800.63.camel@twins> <20080811120231.GC23529@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080811120231.GC23529@elte.hu> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1099 Lines: 23 > That's a rather misleading argument, because klogd as it stands today is > already lossy: you can overflow it with enough printk data. (It's rather That's true, but with at least the timer tick version it would become much worse I think, because there would be a rather low upper limit on the maximum frequency of klogd wakeups. Not fully sure about the RCU version, i guess it would depend on how many CPUs you have (but that one had the problem of "cannot put printks into RCU anymore") BTW if you only care about the console you can always use early_printk() at least for serial/vga/usb debug on x86 -- it will never lose anything (at least as long as you can read the output fast enough) and also works in nearly any context. But of course since it also doesn't log anything to klogd it's probably not a good idea outside debugging. -Andi -- 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/