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 939DEC43217 for ; Wed, 18 May 2022 23:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231645AbiERXiV (ORCPT ); Wed, 18 May 2022 19:38:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231217AbiERXiH (ORCPT ); Wed, 18 May 2022 19:38:07 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 133CAC1EEC for ; Wed, 18 May 2022 16:37:52 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24IN6IoP013725 for ; Wed, 18 May 2022 16:37:51 -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=UBS18O+BsnzFCTIQhXny5YXEO4wIVCIzwj+tQ4lzVAU=; b=Kk1yA29IoHeTQzOk5Z0YomInehR7eRz/cEds+Cfb3ngjghwXRTGZ8yFezu/AdGHqqQHW qmcxx+RPJYfbbQY20GlcvXMBqhDEK7URqp6Yac2tUf7zf1F0IhFxbgqKi/0+EMcjNXrw rMAFqUnod8Uo8K6YzQ9SwjEFRPsv2B6n/c8= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g4dea3tmt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 18 May 2022 16:37:51 -0700 Received: from twshared8307.18.frc3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) 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 16:37:50 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 0C42BF3ED86D; Wed, 18 May 2022 16:37:13 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , Subject: [RFC PATCH v3 14/18] mm: Prepare balance_dirty_pages() for async buffered writes Date: Wed, 18 May 2022 16:37:05 -0700 Message-ID: <20220518233709.1937634-15-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-ORIG-GUID: d4kXw5TUgp40QpwkuEzeAI7WoECK6v0U X-Proofpoint-GUID: d4kXw5TUgp40QpwkuEzeAI7WoECK6v0U 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 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Jan Kara If balance_dirty_pages() gets called for async buffered write, we don't want to wait. Instead we need to indicate to the caller that throttling is needed so that it can stop writing and offload the rest of the write to a context that can block. Signed-off-by: Jan Kara Signed-off-by: Stefan Roesch --- mm/page-writeback.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 89dcc7d8395a..fc3b79acd90b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1545,8 +1545,8 @@ static inline void wb_dirty_limits(struct dirty_thr= ottle_control *dtc) * If we're over `background_thresh' then the writeback threads are woke= n to * perform some writeout. */ -static void balance_dirty_pages(struct bdi_writeback *wb, - unsigned long pages_dirtied) +static int balance_dirty_pages(struct bdi_writeback *wb, + unsigned long pages_dirtied, bool nowait) { struct dirty_throttle_control gdtc_stor =3D { GDTC_INIT(wb) }; struct dirty_throttle_control mdtc_stor =3D { MDTC_INIT(wb, &gdtc_stor)= }; @@ -1566,6 +1566,7 @@ static void balance_dirty_pages(struct bdi_writebac= k *wb, struct backing_dev_info *bdi =3D wb->bdi; bool strictlimit =3D bdi->capabilities & BDI_CAP_STRICTLIMIT; unsigned long start_time =3D jiffies; + int ret =3D 0; =20 for (;;) { unsigned long now =3D jiffies; @@ -1794,6 +1795,10 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, period, pause, start_time); + if (nowait) { + ret =3D -EAGAIN; + break; + } __set_current_state(TASK_KILLABLE); wb->dirty_sleep =3D now; io_schedule_timeout(pause); @@ -1825,6 +1830,7 @@ static void balance_dirty_pages(struct bdi_writebac= k *wb, if (fatal_signal_pending(current)) break; } + return ret; } =20 static DEFINE_PER_CPU(int, bdp_ratelimits); @@ -1906,7 +1912,7 @@ void balance_dirty_pages_ratelimited(struct address= _space *mapping) preempt_enable(); =20 if (unlikely(current->nr_dirtied >=3D ratelimit)) - balance_dirty_pages(wb, current->nr_dirtied); + balance_dirty_pages(wb, current->nr_dirtied, false); =20 wb_put(wb); } --=20 2.30.2