From patchwork Wed May 25 22:34:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 12861790 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 4F145C43217 for ; Wed, 25 May 2022 22:35:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345511AbiEYWfU (ORCPT ); Wed, 25 May 2022 18:35:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345177AbiEYWe7 (ORCPT ); Wed, 25 May 2022 18:34:59 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7BB210FDE for ; Wed, 25 May 2022 15:34:51 -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 24PGtY9c017109 for ; Wed, 25 May 2022 15:34:51 -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=nGh3U+seKW+wqwcOUlFaxxUDiyVe029LznfEhqkjpHqTisFquPfEw+n2SRjBZc4EsXg/ Htx9taWwbAlZwR33WZCZZLOtORytitRPvuO0rVQ9N6pRWM0b8IUAfFBq7e7M8rNa+KV9 R/GiIs3LCmzAIPqqVLghW2HvOhtH/aROyzA= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g93vs9eam-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 25 May 2022 15:34:51 -0700 Received: from snc-exhub201.TheFacebook.com (2620:10d:c085:21d::7) by snc-exhub102.TheFacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Wed, 25 May 2022 15:34:49 -0700 Received: from twshared6696.05.ash7.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Wed, 25 May 2022 15:34:49 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id E7293F9E1B40; Wed, 25 May 2022 15:34:34 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , Subject: [PATCH v5 01/16] mm: Move starting of background writeback into the main balancing loop Date: Wed, 25 May 2022 15:34:17 -0700 Message-ID: <20220525223432.205676-2-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220525223432.205676-1-shr@fb.com> References: <20220525223432.205676-1-shr@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: XqzoTzYNUCiOHAl6-8fUuCiC7J_HkF53 X-Proofpoint-GUID: XqzoTzYNUCiOHAl6-8fUuCiC7J_HkF53 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=2022-05-25_06,2022-05-25_02,2022-02-23_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 7e2da284e427..8e5e003f0093 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1618,6 +1618,19 @@ static void balance_dirty_pages(struct bdi_writeback *wb, } } + /* + * 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_writeback *wb, break; } + /* Start writeback even when in laptop mode */ if (unlikely(!writeback_in_progress(wb))) wb_start_background_writeback(wb); @@ -1814,23 +1828,6 @@ static void balance_dirty_pages(struct bdi_writeback *wb, if (!dirty_exceeded && wb->dirty_exceeded) wb->dirty_exceeded = 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); } static DEFINE_PER_CPU(int, bdp_ratelimits);