Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756935Ab0FSUXv (ORCPT ); Sat, 19 Jun 2010 16:23:51 -0400 Received: from one.firstfloor.org ([213.235.205.2]:41903 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755856Ab0FSUXu (ORCPT ); Sat, 19 Jun 2010 16:23:50 -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> <878w6bphc2.fsf@basil.nowhere.org> Date: Sat, 19 Jun 2010 22:23:48 +0200 In-Reply-To: (Michael Rubin's message of "Sat, 19 Jun 2010 10:49:34 -0700") Message-ID: <87eig2ixez.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 Content-Length: 1254 Lines: 35 Michael Rubin writes: > > I agree. This would put the kernel in a box a bit. Some of them > (sys_sync, periodic writeback, free_more_memory) I feel are generic > enough concepts that with some rewording of the labels they could be > exposed with no issue. "Balance_dirty_pages" is an example where that > won't work. Yes some rewording would be good. > Are there alternatives to this? Maybe tracepoints that are compiled to be on? > A CONFIG_WRITEBACK_DEBUG that would expose this file? The classic way is to put it into debugfs which has a appropiate disclaimer. (although I fear we're weaning apps that depend on debugfs too The growing ftrace user space code seems to all depend on debugfs) > Having this set of info readily available and collected makes > debugging a lot easier. But I admit I am not sure the best way to > expose them. Maybe we just need a simpler writeback path that is not as complicated to debug. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/