From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756135Ab1LMW6z (ORCPT ); Tue, 13 Dec 2011 17:58:55 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:44113 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753356Ab1LMW6w (ORCPT ); Tue, 13 Dec 2011 17:58:52 -0500 Date: Tue, 13 Dec 2011 14:58:51 -0800 From: Andrew Morton To: KAMEZAWA Hiroyuki Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "kosaki.motohiro@jp.fujitsu.com" , rientjes@google.com Subject: Re: [PATCH v4] oom: add trace points for debugging. Message-Id: <20111213145851.c7e5d8fa.akpm@linux-foundation.org> In-Reply-To: <20111213181225.673e19db.kamezawa.hiroyu@jp.fujitsu.com> References: <20111213181225.673e19db.kamezawa.hiroyu@jp.fujitsu.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 13 Dec 2011 18:12:25 +0900 KAMEZAWA Hiroyuki wrote: > Changelog: > - devided into oom tracepoint and task tracepoint. > - task tracepoint traces fork/rename > - oom tracepoint traces modification to oom_score_adj. > > dropped acks because of total design changes. > > From: KAMEZAWA Hiroyuki > Subject: [PATCH] tracepoint: add tracepoints for debugging oom_score_adj. > > oom_score_adj is used for guarding processes from OOM-Killer. One of problem > is that it's inherited at fork(). When a daemon set oom_score_adj and > make children, it's hard to know where the value is set. This sounds like a really thin justification for patching the kernel. "Help! I don't know what my code is doing!". Alternatives would include grepping your source code for "oom_score_adj", or running "strace -f"! I suspect you did have a good reason for making this change, but it wasn't explained very well?