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 DAE51CCA473 for ; Wed, 1 Jun 2022 21:01:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230428AbiFAVB4 (ORCPT ); Wed, 1 Jun 2022 17:01:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230473AbiFAVBy (ORCPT ); Wed, 1 Jun 2022 17:01:54 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AFA61BF173 for ; Wed, 1 Jun 2022 14:01:52 -0700 (PDT) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 251GTTmH015007 for ; Wed, 1 Jun 2022 14:01:52 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=+IYV+ohWMnP9Z2WqVp2E+CnW9cqqI1fK3UacqUP+NEU=; b=TNdvL5H9Nnbr5ngz7PfC+qxRx5KoUDRycNbiHAywt2stgsiwkD+CJvAzRkQJig18OBKK qZAm40cAczX/wnle++9nk7FIfdVUQKDonMs75YhI66e8QeRkrZGvFdICsZ36p7PLwZ0D kKYhyyoqZKqPtXrYDJk0Z01/dwH9VyEofy4= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3gdt5jqff6-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 01 Jun 2022 14:01:52 -0700 Received: from twshared4937.07.ash9.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Wed, 1 Jun 2022 14:01:51 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id B86C6FEB2394; Wed, 1 Jun 2022 14:01:42 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , , Subject: [PATCH v7 01/15] mm: Move starting of background writeback into the main balancing loop Date: Wed, 1 Jun 2022 14:01:27 -0700 Message-ID: <20220601210141.3773402-2-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220601210141.3773402-1-shr@fb.com> References: <20220601210141.3773402-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: 38ZABpBqG0jleG__yDv20SI5M4RPy8bc X-Proofpoint-ORIG-GUID: 38ZABpBqG0jleG__yDv20SI5M4RPy8bc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-01_08,2022-06-01_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Jan Kara We start background writeback if we are over background threshold after exiting the main loop in balance_dirty_pages(). This may result in basing the decision on already stale values (we may have slept for significant amount of time) and it is also inconvenient for refactoring needed for async dirty throttling. Move the check into the main waiting loop. Signed-off-by: Jan Kara Signed-off-by: Stefan Roesch --- mm/page-writeback.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 55c2776ae699..e59c523aed1a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1627,6 +1627,19 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, } } =20 + /* + * In laptop mode, we wait until hitting the higher threshold + * before starting background writeout, and then write out all + * the way down to the lower threshold. So slow writers cause + * minimal disk activity. + * + * In normal mode, we start background writeout at the lower + * background_thresh, to keep the amount of dirty memory low. + */ + if (!laptop_mode && nr_reclaimable > gdtc->bg_thresh && + !writeback_in_progress(wb)) + wb_start_background_writeback(wb); + /* * Throttle it only when the background writeback cannot * catch-up. This avoids (excessively) small writeouts @@ -1657,6 +1670,7 @@ static void balance_dirty_pages(struct bdi_writebac= k *wb, break; } =20 + /* Start writeback even when in laptop mode */ if (unlikely(!writeback_in_progress(wb))) wb_start_background_writeback(wb); =20 @@ -1823,23 +1837,6 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, =20 if (!dirty_exceeded && wb->dirty_exceeded) wb->dirty_exceeded =3D 0; - - if (writeback_in_progress(wb)) - return; - - /* - * In laptop mode, we wait until hitting the higher threshold before - * starting background writeout, and then write out all the way down - * to the lower threshold. So slow writers cause minimal disk activity= . - * - * In normal mode, we start background writeout at the lower - * background_thresh, to keep the amount of dirty memory low. - */ - if (laptop_mode) - return; - - if (nr_reclaimable > gdtc->bg_thresh) - wb_start_background_writeback(wb); } =20 static DEFINE_PER_CPU(int, bdp_ratelimits); --=20 2.30.2