From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 315D3C25B0E for ; Fri, 19 Aug 2022 06:57:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346679AbiHSG5O (ORCPT ); Fri, 19 Aug 2022 02:57:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243277AbiHSG5G (ORCPT ); Fri, 19 Aug 2022 02:57:06 -0400 Received: from out1.migadu.com (out1.migadu.com [IPv6:2001:41d0:2:863f::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60CB6DF09E for ; Thu, 18 Aug 2022 23:57:05 -0700 (PDT) Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1660892223; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lBNrmYPXLIF8oIJg0s80Rs9VguA7/xNAIlxn0aNwRaA=; b=uj8IRehRCxlFt3hWOSyoL+4qmy0+X4f2zuMmfMQsfF9LW5pwGRGbHb6NAwcL9wN29VqTD+ N8Wpimjow1Mg9JqR2jo6hcikZg3pvt5XK2Dn9BjlzhVs5DEEgC9zRjvDWUqFcxxf3fbC+s Ua4qfLEvSeV/e6BJugXcPENsPw3/5tw= MIME-Version: 1.0 Subject: Re: [PATCH] mm: hugetlb: simplify per-node sysfs creation and removal X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: Date: Fri, 19 Aug 2022 14:56:56 +0800 Cc: Muchun Song , rafael@kernel.org, Mike Kravetz , Andrew Morton , Oscar Salvador , David Hildenbrand , linux-kernel@vger.kernel.org, Linux MM Content-Transfer-Encoding: quoted-printable Message-Id: <0F3FE8B0-9ADB-423D-A2FE-2AF1A3A6E619@linux.dev> References: <20220819052137.7985-1-songmuchun@bytedance.com> To: Greg KH X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Aug 19, 2022, at 14:44, Muchun Song wrote: >=20 >=20 >=20 >> On Aug 19, 2022, at 14:32, Greg KH = wrote: >>=20 >> On Fri, Aug 19, 2022 at 01:21:37PM +0800, Muchun Song wrote: >>> The following commit offload per-node sysfs creation and removal to = a kworker and >>> did not say why it is needed. And it also said "I don't know that = this is >>> absolutely required". It seems like the author was not sure as = well. Since it >>> only complicates the code, this patch will revert the changes to = simplify the code. >>>=20 >>> 39da08cb074c ("hugetlb: offload per node attribute registrations") >>=20 >> Any specific reason why you did not cc: the original author of this >> commit, or anyone else on the patch? >=20 > OK. Cc Lee Schermerhorn. Unluckily, I guess the email address is out of date since I just got = bounced mail (Undelivered Mail Returned to Sender). Remove lee.schermerhorn@hp.com = from the Cc list. >=20 >>=20 >>> We could use memory hotplug notifier to do per-node sysfs creation = and removal >>> instead of inserting those operations to node registration and = unregistration. >>> Then, it can reduce the code coupling between node.c and hugetlb.c. = Also, it can >>> simplify the code. >>=20 >> I do not think we had memory hotplug notifier back in 2009 when this >> commit was first written. >=20 > Maybe not. Commit 39da08cb074c is merger in 2009. However, hotplug = notifier mechanism > is merged in 2006. The document is updated in 2007 (see commit = 10020ca246c5). >=20 >>=20 >> How did you test this? Did you use a HUGETLBFS system and verify = that >> everything still works properly? You are deleting a lot of code = (always >> nice), but making sure everything is still operating the same is a = good >> thing. >=20 > I really did the test (through a VM), it works properly. >=20 > Thanks. >=20 >>=20 >> thanks, >>=20 >> greg k-h