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 92B61EB64D9 for ; Mon, 19 Jun 2023 06:54:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229673AbjFSGy1 (ORCPT ); Mon, 19 Jun 2023 02:54:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229992AbjFSGy0 (ORCPT ); Mon, 19 Jun 2023 02:54:26 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF9851A4; Sun, 18 Jun 2023 23:54:24 -0700 (PDT) Received: from dggpemm500014.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Ql0m33pBkzMp5B; Mon, 19 Jun 2023 14:51:15 +0800 (CST) Received: from [10.174.178.120] (10.174.178.120) by dggpemm500014.china.huawei.com (7.185.36.153) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 19 Jun 2023 14:54:22 +0800 Message-ID: <0ce6abb5-bf32-a5dc-c6eb-0a96e12a8ebd@huawei.com> Date: Mon, 19 Jun 2023 14:54:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 CC: , , , , , , , , , , , Subject: Re: [PATCH stable 5.10 1/1] mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block Content-Language: en-US To: References: <20230614061900.3296725-1-mawupeng1@huawei.com> <20230614061900.3296725-2-mawupeng1@huawei.com> <2023061440-showing-happiest-937e@gregkh> <2023061927-parsnip-gauging-86e9@gregkh> From: mawupeng In-Reply-To: <2023061927-parsnip-gauging-86e9@gregkh> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.120] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500014.china.huawei.com (7.185.36.153) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 2023/6/19 14:20, Greg KH wrote: > On Wed, Jun 14, 2023 at 02:45:58PM +0800, mawupeng wrote: >> >> >> On 2023/6/14 14:35, Greg KH wrote: >>> On Wed, Jun 14, 2023 at 02:19:00PM +0800, Wupeng Ma wrote: >>>> From: David Hildenbrand >>>> >>>> virtio-mem soon wants to use offline_and_remove_memory() memory that >>>> exceeds a single Linux memory block (memory_block_size_bytes()). Let's >>>> remove that restriction. >>>> >>>> Let's remember the old state and try to restore that if anything goes >>>> wrong. While re-onlining can, in general, fail, it's highly unlikely to >>>> happen (usually only when a notifier fails to allocate memory, and these >>>> are rather rare). >>>> >>>> This will be used by virtio-mem to offline+remove memory ranges that are >>>> bigger than a single memory block - for example, with a device block >>>> size of 1 GiB (e.g., gigantic pages in the hypervisor) and a Linux memory >>>> block size of 128MB. >>>> >>>> While we could compress the state into 2 bit, using 8 bit is much >>>> easier. >>>> >>>> This handling is similar, but different to acpi_scan_try_to_offline(): >>>> >>>> a) We don't try to offline twice. I am not sure if this CONFIG_MEMCG >>>> optimization is still relevant - it should only apply to ZONE_NORMAL >>>> (where we have no guarantees). If relevant, we can always add it. >>>> >>>> b) acpi_scan_try_to_offline() simply onlines all memory in case >>>> something goes wrong. It doesn't restore previous online type. Let's do >>>> that, so we won't overwrite what e.g., user space configured. >>>> >>>> Reviewed-by: Wei Yang >>>> Cc: "Michael S. Tsirkin" >>>> Cc: Jason Wang >>>> Cc: Pankaj Gupta >>>> Cc: Michal Hocko >>>> Cc: Oscar Salvador >>>> Cc: Wei Yang >>>> Cc: Andrew Morton >>>> Signed-off-by: David Hildenbrand >>>> Link: https://lore.kernel.org/r/20201112133815.13332-28-david@redhat.com >>>> Signed-off-by: Michael S. Tsirkin >>>> Acked-by: Andrew Morton >>>> --- >>>> mm/memory_hotplug.c | 105 +++++++++++++++++++++++++++++++++++++------- >>>> 1 file changed, 89 insertions(+), 16 deletions(-) >>> >>> As you forwarded this patch on, you too need to sign-off on it. >> >> Thanks for reminding me. >> >> Signed-off-by: Ma Wupeng >> >>> >>> Also, what is the git id of the commit in Linus's tree? >> >> Sorry, here is the commit in Linus's tree. >> >> commit 8dc4bb58a146655eb057247d7c9d19e73928715b upstream. > > Please resend the change with both of these things fixed up, so I don't > have to manually do it :) I have resend the patch but use the parent message id for in-reply-to. Sorry. > > thanks, > > greg k-h