From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964998AbWD1Xnd (ORCPT ); Fri, 28 Apr 2006 19:43:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965004AbWD1Xnd (ORCPT ); Fri, 28 Apr 2006 19:43:33 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:4556 "EHLO e36.co.us.ibm.com") by vger.kernel.org with ESMTP id S964998AbWD1Xnc (ORCPT ); Fri, 28 Apr 2006 19:43:32 -0400 Subject: Re: Linux 2.6.17-rc2 - notifier chain problem? From: Chandra Seetharaman Reply-To: sekharan@us.ibm.com To: Andrew Morton Cc: torvalds@osdl.org, ashok.raj@intel.com, Alan Stern , herbert@13thfloor.at, linux-kernel@vger.kernel.org, linux-xfs@oss.sgi.com, xfs-masters@oss.sgi.com In-Reply-To: <20060428162302.79926325.akpm@osdl.org> References: <1146075534.24650.11.camel@linuxchandra> <20060426114348.51e8e978.akpm@osdl.org> <20060426122926.A31482@unix-os.sc.intel.com> <1146082893.24650.27.camel@linuxchandra> <20060426132644.A31761@unix-os.sc.intel.com> <1146265920.7063.133.camel@linuxchandra> <20060428162302.79926325.akpm@osdl.org> Content-Type: text/plain Organization: IBM Date: Fri, 28 Apr 2006 16:43:29 -0700 Message-Id: <1146267809.7063.141.camel@linuxchandra> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2006-04-28 at 16:23 -0700, Andrew Morton wrote: > Chandra Seetharaman wrote: > > > > Looks like the patches I provided is a step backward from where Ashok & > > Andrew were taking the register_cpu_notifier stuff to. > > > > After some discussions with Ashok we both think the following would be > > the right direction: > > 1 revert the changes i pushed recently > > 2 make all usages of register_cpu_notifier to be _init and > > __initdata (if hotplug cpu is defined these are removed) > > 3 export the symbols register_cpu_notifier and > > unregister_cpu_notifier only in CONFIG_HOTPLUG_CPU is defined > > 4 move the hot plug cpu based usages of register_cpu_notifier > > inside #ifdef CONFIG_HOTPLUF_CPU(like xfs's usage). > > > > I have few questions: > > - any problems with the above direction (mainly 3) ? > > - Should we proceed in this direction ? > > - is it too late for 2.6.17 ? if not late how much time do we have ? > > hm. I'm leaning more towards doing something expedient and obvious for > 2.6.17. It's pretty late in the cycle, and the only downside is the loss > of a kbyte or two. Plus I'll be at linuxtag next week and won't be around to > help out. > > So if it's OK, can we do something minimal, revisit it after 2.6.17? - if we are ok with a loss of a kbyte or two, 2.6.17 is fine as is (with my incorrect patches in). - if we want to save that memory, we can revert the two patches and fix xfs to make the register calls only when hotplug cpu is defined. This change is also minimal. It is a step in the right direction. Only downside i can see in reverting my patch is that if there is any other modules that are doing the same as what xfs was doing, we might trip in a similar oops. chandra -- ---------------------------------------------------------------------- Chandra Seetharaman | Be careful what you choose.... - sekharan@us.ibm.com | .......you may get it. ----------------------------------------------------------------------