From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763023AbYDVKOB (ORCPT ); Tue, 22 Apr 2008 06:14:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759566AbYDVKNu (ORCPT ); Tue, 22 Apr 2008 06:13:50 -0400 Received: from cantor.suse.de ([195.135.220.2]:56593 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758985AbYDVKNt (ORCPT ); Tue, 22 Apr 2008 06:13:49 -0400 Date: Tue, 22 Apr 2008 12:13:48 +0200 Message-ID: From: Takashi Iwai To: Stas Sergeev Cc: Andrew Morton , Dmitry Torokhov , Joseph Fannin , linux-kernel@vger.kernel.org Subject: Re: 2.6.25-mm1 (snd-pcsp doesn't like DEBUG_PAGEALLOC) In-Reply-To: <480CD50F.20706@aknet.ru> References: <20080418014757.52fb4a4f.akpm@linux-foundation.org> <20080419021343.GA3503@nineveh.local> <20080418200237.b5a9e805.akpm@linux-foundation.org> <20080419041429.GA8508@anvil.corenet.prv> <20080418212934.bbe84ee2.akpm@linux-foundation.org> <480CD50F.20706@aknet.ru> User-Agent: Wanderlust/2.15.5 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 MULE XEmacs/21.5 (beta28) (fuki) (+CVS-20070806) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Mon, 21 Apr 2008 21:55:27 +0400, Stas Sergeev wrote: > > Hello. > > Takashi Iwai wrote: > >> CONFIG_DEBUG_PAGEALLOC is a very heavy consumer of CPU cycles. I'm not > >> surprised that it would whack what I presume to be a very latency-sensitive > >> driver. > > We can add simply a dependncy to Kconfig if this really matters. > I think this is a bit too heavy-handed. > That thing adds a lot of noise to the sound, > but it doesn't really prevent the driver from > working properly. And perhaps there are > other options with the same effect? > Also, that would motivate people to > optimize DEBUG_PAGEALLOC, while otherwise > they wouldn't know. :) > > What is the problem with the warning > exactly? If it makes problems, we can > just remove it and update the help text > instead, for example. It's no big problem but I just find the phrase "you have to disable..." too strict. It's just a sound-quality problem as you mentioned in the above. BTW, I noticed that the message includes a few line breaks. You need a proper KERN_ prefix for each line in such a case. A fix patch would be appreciated. thanks, Takashi