From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754772Ab0FSIRG (ORCPT ); Sat, 19 Jun 2010 04:17:06 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34709 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754623Ab0FSIRC (ORCPT ); Sat, 19 Jun 2010 04:17:02 -0400 From: Andi Kleen To: Michael Rubin Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, jack@suse.cz, akpm@linux-foundation.org, david@fromorbit.com, hch@lst.de, axboe@kernel.dk Subject: Re: [PATCH 3/3] writeback: tracking subsystems causing writeback References: <1276907415-504-1-git-send-email-mrubin@google.com> <1276907415-504-4-git-send-email-mrubin@google.com> Date: Sat, 19 Jun 2010 10:17:01 +0200 In-Reply-To: <1276907415-504-4-git-send-email-mrubin@google.com> (Michael Rubin's message of "Fri, 18 Jun 2010 17:30:15 -0700") Message-ID: <878w6bphc2.fsf@basil.nowhere.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michael Rubin writes: > > # cat /sys/block/sda/bdi/writeback_stats > balance dirty pages 0 > balance dirty pages waiting 0 > periodic writeback 92024 > periodic writeback exited 0 > laptop periodic 0 > laptop or bg threshold 0 > free more memory 0 > try to free pages 271 > syc_sync 6 > sync filesystem 0 That exports a lot of kernel internals in /sys, presumably read by some applications. What happens with the applications if the kernel internals ever change? Will the application break? It would be bad to not be able to change the kernel because of such an interface. -Andi -- ak@linux.intel.com -- Speaking for myself only.