Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763994AbZC0CWd (ORCPT ); Thu, 26 Mar 2009 22:22:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934559AbZC0CVb (ORCPT ); Thu, 26 Mar 2009 22:21:31 -0400 Received: from yx-out-2324.google.com ([74.125.44.29]:17163 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934500AbZC0CV0 convert rfc822-to-8bit (ORCPT ); Thu, 26 Mar 2009 22:21:26 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=cwy/TgOBLo933IrNUWHPJL2lJxxmpUysClxnqUfdTDKJo3Pjwg9eXtvyOVNLE1LndN 2zrA++Iu0J6ELlT/2vQ2BHDjcVii5Hn8EEsRru585zZlvs0UclnrPm1D9szgNHUUzdgX OCg9yUeH/+Sf/V2Xb1YOGMvhJURrp5m8I35XY= MIME-Version: 1.0 In-Reply-To: <20090326182519.d576d703.akpm@linux-foundation.org> References: <20090325183011.GN32307@mit.edu> <20090325220530.GR32307@mit.edu> <20090326171148.9bf8f1ec.akpm@linux-foundation.org> <20090326174704.cd36bf7b.akpm@linux-foundation.org> <20090326182519.d576d703.akpm@linux-foundation.org> Date: Thu, 26 Mar 2009 19:21:08 -0700 Message-ID: <72dbd3150903261921k7cf728ebhf331e9965630be7e@mail.gmail.com> Subject: Re: Linux 2.6.29 From: David Rees To: Andrew Morton Cc: Linus Torvalds , Theodore Tso , Jesper Krogh , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1890 Lines: 42 On Thu, Mar 26, 2009 at 6:25 PM, Andrew Morton wrote: > Why does everyone just sit around waiting for the kernel to put a new > value into two magic numbers which userspace scripts could have set? > > My /etc/rc.local has been tweaking dirty_ratio, dirty_background_ratio > and swappiness for many years. ?I guess I'm just incredibly advanced. The only people who bother to tune those values are people who get annoyed enough to do the research to see if it's something that's tunable - hackers. Everyone else simply says "man, Linux *sucks*" and lives life hoping it will get better some day. From posts in this thread - even most developers just live with it, and have been doing so for *years*. Even Linux distros don't bother modifying init scripts - they patch them into kernel instead. I routinely watch Fedora kernel changelogs and found these comments in the changelog recently: * Mon Mar 23 2009 xx 2.6.29-2 - Change default swappiness setting from 60 to 30. * Thu Mar 19 2009 xx 2.6.29-0.66.rc8.git4 - Raise default vm dirty data limits from 5/10 to 10/20 percent. Why are the going in the kernel package instead of /etc/sysctl.conf? Why is Fedora deviating from upstream? (probably sqlite performance) Maybe there's a good reason to put them into the kernel - for some reason the latest kernels perform better with those values where the previous ones didn't. But still - why ship those 2 bytes of configuration in a 75MB package instead of one that could be a fraction of that size? Does *any* distro fiddle those bits in userspace instead of patching the kernel? -Dave -- 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/