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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60E77C433FE for ; Wed, 18 May 2022 23:37:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 83D6B8D0007; Wed, 18 May 2022 19:37:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7A0EA8D0002; Wed, 18 May 2022 19:37:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 616608D0007; Wed, 18 May 2022 19:37:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 44DEA8D0002 for ; Wed, 18 May 2022 19:37:52 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 1A97B7EB for ; Wed, 18 May 2022 23:37:52 +0000 (UTC) X-FDA: 79480478784.06.5961267 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf23.hostedemail.com (Postfix) with ESMTP id B8CAF1400CE for ; Wed, 18 May 2022 23:37:33 +0000 (UTC) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24IN6GBV011668 for ; Wed, 18 May 2022 16:37:50 -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=3zHDjbn72NXSBweb9g6a0xThug/NIwNbovojkJVDB2M=; b=di3baeMW3rzcrQoGRLWCiG7GZRUkxeggm5fvoPbuu/EkrYSB1uv+z7CzQgfgLD2qfQbD iD0614dSJ0xYKMPQawmxHAAobxJZO7uXFn4jGgtXTVNa/DDHTQEBgDQlu7i7OBDjXXJa +pl70FPALuSEn1NGYGVEw2kbGyLrmGQv/TQ= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g4frtanqj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 18 May 2022 16:37:50 -0700 Received: from twshared8508.05.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Wed, 18 May 2022 16:37:49 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id F1ED2F3ED869; Wed, 18 May 2022 16:37:12 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , Subject: [RFC PATCH v3 12/18] mm: Move starting of background writeback into the main balancing loop Date: Wed, 18 May 2022 16:37:03 -0700 Message-ID: <20220518233709.1937634-13-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220518233709.1937634-1-shr@fb.com> References: <20220518233709.1937634-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: Vos-a2JiTfbvDNW_Xv23oad8sflN3orD X-Proofpoint-ORIG-GUID: Vos-a2JiTfbvDNW_Xv23oad8sflN3orD X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-18_06,2022-05-17_02,2022-02-23_01 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=fb.com header.s=facebook header.b=di3baeMW; spf=none (imf23.hostedemail.com: domain of "prvs=6137e46c81=shr@fb.com" has no SPF policy when checking 67.231.145.42) smtp.mailfrom="prvs=6137e46c81=shr@fb.com"; dmarc=pass (policy=reject) header.from=fb.com X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B8CAF1400CE X-Stat-Signature: ksq4bkrcfu8w7zy1jcistewib1izxdww X-HE-Tag: 1652917053-482743 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 7e2da284e427..8e5e003f0093 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1618,6 +1618,19 @@ 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 @@ -1648,6 +1661,7 @@ 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 @@ -1814,23 +1828,6 @@ 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