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 F3A55C433EF for ; Mon, 11 Jul 2022 08:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230484AbiGKIus (ORCPT ); Mon, 11 Jul 2022 04:50:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230307AbiGKIuZ (ORCPT ); Mon, 11 Jul 2022 04:50:25 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 204E31EEE1 for ; Mon, 11 Jul 2022 01:50:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657529414; x=1689065414; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tbVtvIK8XMk4xb1SU8xCdADdmx3jSPLB5EdXqTq3PBc=; b=Ux06BiEHYrjtywykn3AJ+imdmz96I/Fzz+OFXLy2lBUrgxb9ZJdYJNG5 ycxkXrQZzU3psGcKJb4vZ1qCUeQrHTgH5jdvloIgVRxVSJye2cYm3QuIl Imc0zhGPnr9W7iCp3qio2BbYAd+C8dCIK/s8wX/Uv6dGCWBWq6TaWiQzj oNKHfMFlPCvo6NJkF9E67eH9ublDSvLz+RrM7VFkRL3awfwJL3brxH+45 wy/kAWMogLdZKMb3+jSZCkphjf7IpLB79cCm/+yvp4kKpflQA1jtwUglA hOBOSG69/cRtfQHAKOIycth1uYp642LZ8aBdBfO9tgEvXQsKFWOwwdgtU g==; X-IronPort-AV: E=McAfee;i="6400,9594,10404"; a="284637852" X-IronPort-AV: E=Sophos;i="5.92,262,1650956400"; d="scan'208";a="284637852" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2022 01:50:13 -0700 X-IronPort-AV: E=Sophos;i="5.92,262,1650956400"; d="scan'208";a="652374162" Received: from yhuang6-mobl1.sh.intel.com ([10.238.5.168]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2022 01:50:11 -0700 From: Huang Ying To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Baolin Wang , Zi Yan , Yang Shi Subject: [PATCH -V2 5/7] migrate_pages(): fix failure counting for THP on -ENOSYS Date: Mon, 11 Jul 2022 16:49:46 +0800 Message-Id: <20220711084948.274787-6-ying.huang@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220711084948.274787-1-ying.huang@intel.com> References: <20220711084948.274787-1-ying.huang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If THP or hugetlbfs page migration isn't supported, unmap_and_move() or unmap_and_move_huge_page() will return -ENOSYS. For THP, splitting will be tried, but if splitting doesn't succeed, the THP will be left in "from" list wrongly. If some other pages are retried, the THP migration failure will counted again. This is fixed via moving the failure THP from "from" to "ret_pages". Another issue of the original code is that the unsupported failure processing isn't consistent between THP and hugetlbfs page. Make them consistent in this patch to make the code easier to be understood too. Signed-off-by: "Huang, Ying" Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") Reviewed-by: Baolin Wang Cc: Zi Yan Cc: Yang Shi --- mm/migrate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 4bceba143db0..8cce73b7c046 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1192,10 +1192,8 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, * tables or check whether the hugepage is pmd-based or not before * kicking migration. */ - if (!hugepage_migration_supported(page_hstate(hpage))) { - list_move_tail(&hpage->lru, ret); + if (!hugepage_migration_supported(page_hstate(hpage))) return -ENOSYS; - } if (page_count(hpage) == 1) { /* page was freed from under us. So we are done. */ @@ -1392,6 +1390,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, * page will be put back * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list + * -ENOSYS: stay on the from list * Other errno: put on ret_pages list then splice to * from list */ @@ -1421,6 +1420,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, } nr_failed_pages += nr_subpages; + list_move_tail(&page->lru, &ret_pages); break; case -ENOMEM: /* -- 2.30.2