From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758394Ab2ECULR (ORCPT ); Thu, 3 May 2012 16:11:17 -0400 Received: from merlin.infradead.org ([205.233.59.134]:57513 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754586Ab2ECULQ convert rfc822-to-8bit (ORCPT ); Thu, 3 May 2012 16:11:16 -0400 Message-ID: <1336075862.6509.10.camel@twins> Subject: Re: [PATCH RESEND 1/3] printk: convert byte-buffer to variable-length record buffer From: Peter Zijlstra To: Linus Torvalds Cc: Kay Sievers , Greg Kroah-Hartmann , Ingo Molnar , linux-kernel@vger.kernel.org Date: Thu, 03 May 2012 22:11:02 +0200 In-Reply-To: References: <1336004953.4240.9.camel@mop> <1336074483.6509.3.camel@twins> <1336075373.6509.9.camel@twins> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-05-03 at 13:09 -0700, Linus Torvalds wrote: > On Thu, May 3, 2012 at 1:02 PM, Peter Zijlstra wrote: > > > > Thing is, with bonkers stuff like usb-console and kms/drm that's a _lot_ > > of code running under the logbuf/console locks. > > The top-level console lock shouldn't be a problem - we use trylock and > delay if it is held. > > It's the lower-level driver-specific locks that screw us up. And quite > frankly, I am *not* willing to say that that is a printk() problem. > That is purely a "USB serial console is damn well broken" issue, and > should not be considered a limitation of printk. I'm happy to call all that broken ;-)