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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 2FCC1C433DB for ; Tue, 23 Mar 2021 10:49:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4091619CE for ; Tue, 23 Mar 2021 10:49:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229746AbhCWKt2 (ORCPT ); Tue, 23 Mar 2021 06:49:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:40418 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230299AbhCWKtH (ORCPT ); Tue, 23 Mar 2021 06:49:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 45367AD6D; Tue, 23 Mar 2021 10:49:06 +0000 (UTC) Date: Tue, 23 Mar 2021 11:49:03 +0100 From: Oscar Salvador To: Andrew Morton Cc: Mike Kravetz , Vlastimil Babka , David Hildenbrand , Michal Hocko , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 2/5] mm,compaction: Let isolate_migratepages_{range,block} return error codes Message-ID: <20210323104858.GA7776@linux> References: <20210319132004.4341-1-osalvador@suse.de> <20210319132004.4341-3-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210319132004.4341-3-osalvador@suse.de> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 19, 2021 at 02:20:01PM +0100, Oscar Salvador wrote: > Currently, isolate_migratepages_{range,block} and their callers use > a pfn == 0 vs pfn != 0 scheme to let the caller know whether there was > any error during isolation. > This does not work as soon as we need to start reporting different error > codes and make sure we pass them down the chain, so they are properly > interpreted by functions like e.g: alloc_contig_range. > > Let us rework isolate_migratepages_{range,block} so we can report error > codes. > Since isolate_migratepages_block will stop returning the next pfn to be > scanned, we reuse the cc->migrate_pfn field to keep track of that. > > Signed-off-by: Oscar Salvador > Acked-by: Vlastimil Babka Hi Andrew, I realized a missed place wrt. error handling. could you squash this on top? diff --git a/mm/compaction.c b/mm/compaction.c index cd090a675321..9b989fc3168d 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -809,6 +809,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, bool skip_on_failure = false; unsigned long next_skip_pfn = 0; bool skip_updated = false; + int ret = 0; cc->migrate_pfn = low_pfn; @@ -877,8 +878,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (fatal_signal_pending(current)) { cc->contended = true; + ret = -EINTR; - low_pfn = 0; goto fatal_pending; } @@ -1134,7 +1135,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, cc->migrate_pfn = low_pfn; - return 0; + return ret; } Thanks a lot -- Oscar Salvador SUSE L3