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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D748BC33CB1 for ; Mon, 27 Jan 2020 13:47:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADDDC20716 for ; Mon, 27 Jan 2020 13:47:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580132827; bh=tVZSvPbMuhT+sfRNfYMyVDZvO44e3dvytoFF7axcFag=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1Z4Jf98Dsa/KqWorUrAIqhILQHbAU9C/UadynnqVZP5jGUTK4iFG/MYR4qjAd+eBy osvC5ojZpRJqaKMaegrsfbV9vQ2YX69u0fUGL8fKy8regwCeKe/OkOcTUnHthjS21N zThJlIqZCycWxIRa3zGQVJyJHAcyb7dE8F5hHBf8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728465AbgA0NrG (ORCPT ); Mon, 27 Jan 2020 08:47:06 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:33532 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725828AbgA0NrG (ORCPT ); Mon, 27 Jan 2020 08:47:06 -0500 Received: by mail-wr1-f65.google.com with SMTP id b6so11394641wrq.0; Mon, 27 Jan 2020 05:47:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=RrWpQE/VnIZwikbFGvSuSK1v5GexTEwUzERkPHgg/GE=; b=SPXRZ7N9u8vERq5HcrxbMrXfD3/tHsxJ5maOZEErBoqt55UaePjEnuRN4ZBkNEW48w eq0gLsF+fv5GG1dEPigzpiKZFV8KGi+SkSo0EhBgVOE9wMNYjc8oBSfc90oms23Qu2nl uSlT11Vyktafb1/LOcC42WJjSx9uxm1KN4xOFzmZ5rNKulYM/RiDtmbm5v19pF5dcYcf jPDGzHAJaObHjMs4JjwOlIE+jXOvg0l7eCmCEaZYDdC0Ui6X7xIf5u0T+0tpN3qtWGC5 cle48SUXw6+inVToHmu11HgmL8meRUmAafKftFAPqyIlhB/zf6M1aakk0h4iUcWK6FOb SGaQ== X-Gm-Message-State: APjAAAWf/si+2/W42BJ16g1P9tkTOV+8hVrTZhNgVEyjPlX+eiVk48ZT tJHbep5OftF8WT2CS+/2fYA= X-Google-Smtp-Source: APXvYqxuzSy7u6AvBpDEBh+3XBuTPRlHz0vMV4tjwz6eWfNfOphsZWVdcAae62Dpz1a+TxrgovrIhQ== X-Received: by 2002:adf:fc03:: with SMTP id i3mr22197142wrr.306.1580132824077; Mon, 27 Jan 2020 05:47:04 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id m7sm18599014wma.39.2020.01.27.05.47.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jan 2020 05:47:03 -0800 (PST) Date: Mon, 27 Jan 2020 14:47:02 +0100 From: Michal Hocko To: Dan Williams Cc: David Hildenbrand , Andrew Morton , stable , Vishal Verma , Pavel Tatashin , Dave Hansen , Linux MM , Linux Kernel Mailing List Subject: Re: [PATCH] mm/memory_hotplug: Fix remove_memory() lockdep splat Message-ID: <20200127134702.GJ1183@dhcp22.suse.cz> References: <4d0334e2-c4e7-6d3f-99ba-2ca0495e1549@redhat.com> <64902066-51dd-9693-53fc-4a5975c58409@redhat.com> <516aa930-9b64-b377-557c-5413ed9fe336@redhat.com> <20200124124512.GT29276@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 24-01-20 10:04:52, Dan Williams wrote: > On Fri, Jan 24, 2020 at 4:56 AM Michal Hocko wrote: > > > > On Fri 10-01-20 13:27:24, Dan Williams wrote: > > > On Fri, Jan 10, 2020 at 9:42 AM David Hildenbrand wrote: > > [...] > > > > For your reference (roughly 5 months ago, so not that old) > > > > > > > > https://lkml.kernel.org/r/20190724143017.12841-1-david@redhat.com > > > > > > Oh, now I see the problem. You need to add that lock so far away from > > > the __add_memory() to avoid lock inversion problems with the > > > acpi_scan_lock. The organization I was envisioning would not work > > > without deeper refactoring. > > > > Sorry to come back to this late. Has this been resolved? > > The mem_hotplug_lock lockdep splat fix in this patch has not landed. > David and I have not quite come to consensus on how to resolve online > racing removal. IIUC David wants that invalidation to be > pages_correctly_probed(), I would prefer it to be directly tied to the > object, struct memory_block, that remove_memory_block_devices() has > modified, mem->section_count = 0. I was asking about this part and I can see you have already posted a patch[1] and I do not see any reason for not merging it. [1] http://lkml.kernel.org/r/157991441887.2763922.4770790047389427325.stgit@dwillia2-desk3.amr.corp.intel.com -- Michal Hocko SUSE Labs