From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx153.postini.com [74.125.245.153]) by kanga.kvack.org (Postfix) with SMTP id 20FC46B0068 for ; Mon, 1 Oct 2012 02:55:09 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 16CFF3EE0BC for ; Mon, 1 Oct 2012 15:55:07 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id DF61445DEBC for ; Mon, 1 Oct 2012 15:55:06 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id B5AAF45DEBE for ; Mon, 1 Oct 2012 15:55:06 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id A0A5B1DB803B for ; Mon, 1 Oct 2012 15:55:06 +0900 (JST) Received: from g01jpexchkw06.g01.fujitsu.local (g01jpexchkw06.g01.fujitsu.local [10.0.194.45]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 29AE71DB8040 for ; Mon, 1 Oct 2012 15:55:06 +0900 (JST) Message-ID: <50693E30.3010006@jp.fujitsu.com> Date: Mon, 1 Oct 2012 15:54:40 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [PATCH 2/4] memory-hotplug: add node_device_release References: <1348724705-23779-1-git-send-email-wency@cn.fujitsu.com> <1348724705-23779-3-git-send-email-wency@cn.fujitsu.com> <5064EA5A.3080905@jp.fujitsu.com> <5064FDCA.1020504@jp.fujitsu.com> <5065740A.2000502@jp.fujitsu.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: wency@cn.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, minchan.kim@gmail.com, akpm@linux-foundation.org Hi Kosaki-san, 2012/09/29 7:19, KOSAKI Motohiro wrote: >>>> I don't understand it. How can we get rid of the warning? >>> >>> See cpu_device_release() for example. >> >> If we implement a function like cpu_device_release(), the warning >> disappears. But the comment says in the function "Never copy this way...". >> So I think it is illegal way. > > What does "illegal" mean? The "illegal" means the code should not be mimicked. > You still haven't explain any benefit of your code. If there is zero > benefit, just kill it. > I believe everybody think so. > > Again, Which benefit do you have? The patch has a benefit to delets a warning message. > >>>>> Why do we need this node_device_release() implementation? >>>> >>>> I think that this is a manner of releasing object related kobject. >>> >>> No. Usually we never call memset() from release callback. >> >> What we want to release is a part of array, not a pointer. >> Therefore, there is only this way instead of kfree(). > > Why? Before your patch, we don't have memset() and did work it. If we does not apply the patch, a warning message is shown. So I think it did not work well. > I can't understand what mean "only way". For deleting a warning message, I created a node_device_release(). In the manner of releasing kobject, the function frees a object related to the kobject. So most functions calls kfree() for releasing it. In node_device_release(), we need to free a node struct. If the node struct is pointer, I can free it by kfree. But the node struct is a part of node_devices[] array. I cannot free it. So I filled the node struct with 0. But you think it is not good. Do you have a good solution? Thanks, Yasuaki Ishimatsu > -- > 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/ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org