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 3B7F8C433EF for ; Thu, 16 Jun 2022 21:25:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378660AbiFPVZS (ORCPT ); Thu, 16 Jun 2022 17:25:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229538AbiFPVZS (ORCPT ); Thu, 16 Jun 2022 17:25:18 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9921360DAF for ; Thu, 16 Jun 2022 14:25:17 -0700 (PDT) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25GKPWeM024960 for ; Thu, 16 Jun 2022 14:25:17 -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=lnXyN5VaZy0jkf97IXIxihXSHAqSNnJcPl4o74ExLjQfPVwLMsID3kE8O5bN7ICiVJ00 OYa+gdNnJBWq0vMjeq5l6P3XvmFJsVqpNJL6n5jip9rKv1hQE+npX5l3e7tWVA8PDLHj ZcJJ1KPGAuhlEbGWQJw8i+vpnlLmR9sz+N8= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3gqt6fpd4m-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 16 Jun 2022 14:25:16 -0700 Received: from twshared25107.07.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Thu, 16 Jun 2022 14:25:15 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 8B053108B7093; Thu, 16 Jun 2022 14:22:23 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , , , Subject: [PATCH v9 01/14] mm: Move starting of background writeback into the main balancing loop Date: Thu, 16 Jun 2022 14:22:08 -0700 Message-ID: <20220616212221.2024518-2-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220616212221.2024518-1-shr@fb.com> References: <20220616212221.2024518-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: UceYNZ3QYzQpdMo27TFjMnT_4bVPFPkm X-Proofpoint-ORIG-GUID: UceYNZ3QYzQpdMo27TFjMnT_4bVPFPkm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-16_18,2022-06-16_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