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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 59F41C28CF6 for ; Wed, 1 Aug 2018 11:09:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DC622083D for ; Wed, 1 Aug 2018 11:09:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DC622083D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388751AbeHAMy6 (ORCPT ); Wed, 1 Aug 2018 08:54:58 -0400 Received: from ozlabs.org ([203.11.71.1]:51313 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730915AbeHAMy6 (ORCPT ); Wed, 1 Aug 2018 08:54:58 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 41gVv81cFZz9s0R; Wed, 1 Aug 2018 21:09:40 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au From: Michael Ellerman To: Michal Hocko , John Allen Cc: n-horiguchi@ah.jp.nec.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, mgorman@suse.de Subject: Re: Infinite looping observed in __offline_pages In-Reply-To: <20180725200336.GP28386@dhcp22.suse.cz> References: <20180725181115.hmlyd3tmnu3mn3sf@p50.austin.ibm.com> <20180725200336.GP28386@dhcp22.suse.cz> Date: Wed, 01 Aug 2018 21:09:39 +1000 Message-ID: <87r2jifimk.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michal Hocko writes: > On Wed 25-07-18 13:11:15, John Allen wrote: > [...] >> Does a failure in do_migrate_range indicate that the range is unmigratable >> and the loop in __offline_pages should terminate and goto failed_removal? Or >> should we allow a certain number of retrys before we >> give up on migrating the range? > > Unfortunatelly not. Migration code doesn't tell a difference between > ephemeral and permanent failures. What's to stop an ephemeral failure happening repeatedly? cheers