From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f199.google.com (mail-ot0-f199.google.com [74.125.82.199]) by kanga.kvack.org (Postfix) with ESMTP id 29B4F6B026E for ; Mon, 4 Dec 2017 09:05:07 -0500 (EST) Received: by mail-ot0-f199.google.com with SMTP id c41so9384176otc.18 for ; Mon, 04 Dec 2017 06:05:07 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id y16sor4666817oia.312.2017.12.04.06.05.06 for (Google Transport Security); Mon, 04 Dec 2017 06:05:06 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20171204112855.GA6373@samekh> References: <4e21a27570f665793debf167c8567c6752116d0a.1511433386.git.ar@linux.vnet.ibm.com> <20171129004913.GB1469@linux-l9pv.suse> <20171129015229.GD1469@linux-l9pv.suse> <20171204112855.GA6373@samekh> From: "Rafael J. Wysocki" Date: Mon, 4 Dec 2017 15:05:05 +0100 Message-ID: Subject: Re: [PATCH v2 2/5] mm: memory_hotplug: Remove assumption on memory state before hotremove Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Reale Cc: joeyli , "linux-arm-kernel@lists.infradead.org" , Linux Kernel Mailing List , Linux Memory Management List , m.bielski@virtualopensystems.com, arunks@qti.qualcomm.com, Mark Rutland , scott.branden@broadcom.com, Will Deacon , qiuxishi@huawei.com, Catalin Marinas , Michal Hocko , Rafael Wysocki , ACPI Devel Maling List On Mon, Dec 4, 2017 at 12:28 PM, Andrea Reale wrote: > Hi Joey, > > and thanks for your comments. Response inline: > [cut] >> >> So, the BUG() is useful to capture state issue in memory subsystem. But, I >> understood your concern about the two steps offline/remove from userland. >> >> Maybe we should move the BUG() to somewhere but not just remove it. Or if >> we think that the BUG() is too intense, at least we should print out a error >> message, and ACPI should checks the return value from subsystem to >> interrupt memory-hotplug process. > > In this patchset, BUG() is moved to acpi_memory_remove_memory(), > the caller of arch_remove_memory(). However, I agree with Michal, that > we should not BUG() here but rather halt the hotremove process and print > some errors. > Is there any state in ACPI that should be undone in case of hotremove > errors or we can just stop the process "halfway"? I have to recall a couple of things before answering this question, so that may take some time. Thanks, Rafael -- 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