Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 2 Oct 2001 13:14:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 2 Oct 2001 13:14:33 -0400 Received: from vasquez.zip.com.au ([203.12.97.41]:48401 "EHLO vasquez.zip.com.au") by vger.kernel.org with ESMTP id ; Tue, 2 Oct 2001 13:14:25 -0400 Message-ID: <3BB9F4DC.423EC6B7@zip.com.au> Date: Tue, 02 Oct 2001 10:09:48 -0700 From: Andrew Morton X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.9-ac12 i686) X-Accept-Language: en MIME-Version: 1.0 To: Crutcher Dunnavant CC: linux-kernel@vger.kernel.org Subject: Re: printk while interrupts are disabled In-Reply-To: <3BB9A6F4.6BDDAA81@berlin.de>, <3BB9A6F4.6BDDAA81@berlin.de>; from n.roos@berlin.de on Tue, Oct 02, 2001 at 01:37:24PM +0200 <20011002102210.B1630@mueller.datastacks.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Crutcher Dunnavant wrote: > > ++ 02/10/01 13:37 +0200 - Norbert Roos: > > Hello! > > > > Simple question: Do printk()s get printed while interrupts are disabled > > (after cli)? > > They get stuffed into a buffer to be printed later. It is possible to > overflow that buffer, and lose some of your printk messages. Not quite - a printk from cli() or hardirq context will normally come out immediately. The only time the deferred buffering thing happens is if the console semaphore is found to be already held on entry to printk(). ie: there is already a printk in progress on another CPU or on this CPU in non-interrupt context. The buffered printk output will be printed by the current console-sem owner before it releases the semaphore. - 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/