From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f70.google.com (mail-pl0-f70.google.com [209.85.160.70]) by kanga.kvack.org (Postfix) with ESMTP id E22C46B0006 for ; Wed, 23 May 2018 04:16:13 -0400 (EDT) Received: by mail-pl0-f70.google.com with SMTP id x32-v6so13713482pld.16 for ; Wed, 23 May 2018 01:16:13 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id u6-v6si18515239pls.462.2018.05.23.01.16.12 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 23 May 2018 01:16:12 -0700 (PDT) Date: Wed, 23 May 2018 10:16:09 +0200 From: Michal Hocko Subject: Re: [RFC] Checking for error code in __offline_pages Message-ID: <20180523081609.GG20441@dhcp22.suse.cz> References: <20180523073547.GA29266@techadventures.net> <20180523075239.GF20441@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180523075239.GF20441@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Oscar Salvador Cc: linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@oracle.com, akpm@linux-foundation.org On Wed 23-05-18 09:52:39, Michal Hocko wrote: [...] > Yeah, the current code is far from optimal. We > used to have a retry count but that one was removed exactly because of > premature failures. There are three things here > 1) zone_movable should contain any bootmem or otherwise non-migrateable > pages > 2) start_isolate_page_range should fail when seeing such pages - maybe > has_unmovable_pages is overly optimistic and it should check all > pages even in movable zones. > 3) migrate_pages should really tell us whether the failure is temporal > or permanent. I am not sure we can do that easily though. 2) should be the most simple one for now. Could you give it a try? Btw. the exact configuration that led to boothmem pages in zone_movable would be really appreciated: ---