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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6561ECDB465 for ; Mon, 16 Oct 2023 22:24:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232985AbjJPWYu (ORCPT ); Mon, 16 Oct 2023 18:24:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229943AbjJPWYt (ORCPT ); Mon, 16 Oct 2023 18:24:49 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EA2F9B for ; Mon, 16 Oct 2023 15:24:48 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD13BC433C7; Mon, 16 Oct 2023 22:24:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1697495087; bh=WcVE8yyJcEXti/hXCV2936miKvhj3h/0SSSv4bhKryY=; h=Date:To:From:Subject:From; b=0bnuxrpqrJvENi/ZDLs3teo3W7VABk2FmegPdwfq5nTx2HaNbzOWtzdvzVZFqpZoJ 3GkzkCXtMs2DL+0YQjGp6QC9gAxKmGHgPRbWK+sq88fSeuZ4dLOfuKWywPPsAHXwXp iNIyyqnes1VlmuW55Rqxj0TsWNZCZTk7XN5UiLJQ= Date: Mon, 16 Oct 2023 15:24:47 -0700 To: mm-commits@vger.kernel.org, ying.huang@intel.com, willy@infradead.org, david@redhat.com, baolin.wang@linux.alibaba.com, ziy@nvidia.com, akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-migrate-correct-nr_failed-in-migrate_pages_sync.patch removed from -mm tree Message-Id: <20231016222447.AD13BC433C7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/migrate: correct nr_failed in migrate_pages_sync() has been removed from the -mm tree. Its filename was mm-migrate-correct-nr_failed-in-migrate_pages_sync.patch This patch was dropped because an updated version will be merged ------------------------------------------------------ From: Zi Yan Subject: mm/migrate: correct nr_failed in migrate_pages_sync() Date: Mon, 9 Oct 2023 16:32:31 -0400 In the upstream tree, large folios can be migrated via move_pages() syscall and there is no VM_BUG_ON in do_move_pages_to_node() but pages left in the source page list will not be returned to LRU lists. This is from my code inspection and I have not reproduced it on upstream tree yet. nr_failed was missing the rc value from migrate_pages_batch() and can cause a mismatch between migrate_pages() return value and the number of not migrated pages, i.e., when the return value of migrate_pages() is 0, there are still pages left in the from page list. It will happen when a non-PMD THP large folio fails to migrate due to -ENOMEM and is split successfully but not all the split pages are not migrated, migrate_pages_batch() would return non-zero, but astats.nr_thp_split = 0. nr_failed would be 0 and returned to the caller of migrate_pages(), but the not migrated pages are left in the from page list without being added back to LRU lists. Link: https://lkml.kernel.org/r/20231009203231.1715845-2-zi.yan@sent.com Fixes: 2ef7dbb26990 ("migrate_pages: try migrate in batch asynchronously firstly") Signed-off-by: Zi Yan Cc: Baolin Wang Cc: David Hildenbrand Cc: Huang Ying Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/migrate.c~mm-migrate-correct-nr_failed-in-migrate_pages_sync +++ a/mm/migrate.c @@ -1834,7 +1834,7 @@ static int migrate_pages_sync(struct lis return rc; } stats->nr_thp_failed += astats.nr_thp_split; - nr_failed += astats.nr_thp_split; + nr_failed += rc + astats.nr_thp_split; /* * Fall back to migrate all failed folios one by one synchronously. All * failed folios except split THPs will be retried, so their failure _ Patches currently in -mm which might be from ziy@nvidia.com are