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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED 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 57517C11F68 for ; Thu, 1 Jul 2021 01:51:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 434CB61476 for ; Thu, 1 Jul 2021 01:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238479AbhGAByT (ORCPT ); Wed, 30 Jun 2021 21:54:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:43820 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238427AbhGAByT (ORCPT ); Wed, 30 Jun 2021 21:54:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 033C86105A; Thu, 1 Jul 2021 01:51:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625104309; bh=kfFHHb408x5/Xe3br+j7sBP8MtK3lQSIzDoD9RrJpQs=; h=Date:From:To:Subject:In-Reply-To:From; b=qGULMZS6MsaS+8i9UyQ/skBZuWJiyDsG9eCQe5bKCJOLUCvlZu1ZHnXOgDzPwJ6WO LdV5hop2vfWc5R30oZZOgbossXyuwMIVvK222wmIiDYBNpw9rhWHpblpTyo15CqmBu cjL/R3NBbrcz89n8ji6zbfrouEhVgMdMEWjOyd/4= Date: Wed, 30 Jun 2021 18:51:48 -0700 From: Andrew Morton To: akpm@linux-foundation.org, borntraeger@de.ibm.com, gerald.schaefer@linux.ibm.com, gor@linux.ibm.com, hca@linux.ibm.com, hughd@google.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mgorman@suse.de, mhocko@suse.com, mm-commits@vger.kernel.org, shy828301@gmail.com, torvalds@linux-foundation.org, ying.huang@intel.com, ziy@nvidia.com Subject: [patch 087/192] mm: migrate: don't split THP for misplaced NUMA page Message-ID: <20210701015148.gUkYuLq9J%akpm@linux-foundation.org> In-Reply-To: <20210630184624.9ca1937310b0dd5ce66b30e7@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Yang Shi Subject: mm: migrate: don't split THP for misplaced NUMA page The old behavior didn't split THP if migration is failed due to lack of memory on the target node. But the THP migration does split THP, so keep the old behavior for misplaced NUMA page migration. Link: https://lkml.kernel.org/r/20210518200801.7413-6-shy828301@gmail.com Signed-off-by: Yang Shi Acked-by: Mel Gorman Cc: Christian Borntraeger Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Huang Ying Cc: Hugh Dickins Cc: Kirill A. Shutemov Cc: Michal Hocko Cc: Vasily Gorbik Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/migrate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/migrate.c~mm-migrate-dont-split-thp-for-misplaced-numa-page +++ a/mm/migrate.c @@ -1423,6 +1423,7 @@ int migrate_pages(struct list_head *from int swapwrite = current->flags & PF_SWAPWRITE; int rc, nr_subpages; LIST_HEAD(ret_pages); + bool nosplit = (reason == MR_NUMA_MISPLACED); trace_mm_migrate_pages_start(mode, reason); @@ -1494,8 +1495,9 @@ retry: /* * When memory is low, don't bother to try to migrate * other pages, just exit. + * THP NUMA faulting doesn't split THP to retry. */ - if (is_thp) { + if (is_thp && !nosplit) { if (!try_split_thp(page, &page2, from)) { nr_thp_split++; goto retry; _