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From: Muchun Song In-Reply-To: Date: Fri, 19 Aug 2022 14:44:13 +0800 Cc: Muchun Song , rafael@kernel.org, Mike Kravetz , Andrew Morton , Oscar Salvador , David Hildenbrand , linux-kernel@vger.kernel.org, Linux MM , lee.schermerhorn@hp.com Content-Transfer-Encoding: quoted-printable Message-Id: References: <20220819052137.7985-1-songmuchun@bytedance.com> To: Greg KH X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660891462; a=rsa-sha256; cv=none; b=iz/gLruOWBFA37d5L8z772r4vy4CroBlucnI3uSjWQi18SxA3W9ahxypmEq5kWJR6YXAzF uVkkrIH4jhemzPZzg4FxDo0ususUdBg5MO/M4EZesCvks5hCtdNY4xN9xzXV/XAZgfHZRR Hi5SVVXAfhdAsFcMcLI0lIsqBk3Il88= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=hhwxA7RO; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf07.hostedemail.com: domain of muchun.song@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=muchun.song@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660891462; h=from:from:sender: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:dkim-signature; bh=wuABtezSM3SWmKjuAZiIEnIo/HBbdIYMcf6ubm4bNLY=; b=Ib/6+SliLSfCXzor3dOkTD/V5Ahbht77ud35rL669zeq0xdKIQAksMgDSzyOojC5dCY1UE fDqGx6ASuymRQGxA5dwqARwzV1eqLH5q9rxaFmf+qsolmC67XrO4EULfTBhDT/unHrkP3M 1D72RjLoeBXr2F4BNzPF6BE8EuS8dfA= Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=hhwxA7RO; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf07.hostedemail.com: domain of muchun.song@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=muchun.song@linux.dev X-Rspam-User: X-Stat-Signature: mp48qexp1ciqr53sm8rx5armtgru4es1 X-Rspamd-Queue-Id: 66A9E40016 X-Rspamd-Server: rspam03 X-HE-Tag: 1660891462-608292 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > 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? OK. Cc Lee Schermerhorn. >=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. 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 > 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. I really did the test (through a VM), it works properly. Thanks. >=20 > thanks, >=20 > greg k-h