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 6EA43C433EF for ; Wed, 8 Jun 2022 17:25:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231243AbiFHRZf (ORCPT ); Wed, 8 Jun 2022 13:25:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231459AbiFHRZK (ORCPT ); Wed, 8 Jun 2022 13:25:10 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D5292B19E for ; Wed, 8 Jun 2022 10:20:51 -0700 (PDT) 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 258FPTJf031115 for ; Wed, 8 Jun 2022 10:20:51 -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=NdvWe67YNsLgboqtQSfBVdFzVUFCjXf2l75TyQfe1vU=; b=q3sNiqpH95Smnq1UVno8LT6G64e1ukPrvvCFfv+S7HIKS8utnVdACAf7gpSbTo17wslP iCgl5GyjIhhAre08Xx5UWkAsXIVKxtqdoMqzgBhivHiJGUnBlx0dd0kyaQCaySB3z+h1 3e/Q4qBhJf1EIfcW68GvpzA/QP6kpuKZNpA= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ghtnycfh0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 08 Jun 2022 10:20:51 -0700 Received: from twshared22934.08.ash9.facebook.com (2620:10d:c085:208::f) by mail.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, 8 Jun 2022 10:20:50 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 98263103BFB59; Wed, 8 Jun 2022 10:17:43 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , , , Christoph Hellwig Subject: [PATCH v8 03/14] mm: Add balance_dirty_pages_ratelimited_flags() function Date: Wed, 8 Jun 2022 10:17:30 -0700 Message-ID: <20220608171741.3875418-4-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220608171741.3875418-1-shr@fb.com> References: <20220608171741.3875418-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: tta71ZeFb8qNEwsUi7yjjqiq4YciQFMi X-Proofpoint-GUID: tta71ZeFb8qNEwsUi7yjjqiq4YciQFMi 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=2022-06-08_05,2022-06-07_02,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Jan Kara This adds the helper function balance_dirty_pages_ratelimited_flags(). It adds the parameter flags to balance_dirty_pages_ratelimited(). The flags parameter is passed to balance_dirty_pages(). For async buffered writes the flag value will be BDP_ASYNC. 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. The new helper function is also used by balance_dirty_pages_ratelimited()= . Signed-off-by: Jan Kara Signed-off-by: Stefan Roesch Reviewed-by: Christoph Hellwig --- include/linux/writeback.h | 7 ++++++ mm/page-writeback.c | 48 +++++++++++++++++++++++++-------------- 2 files changed, 38 insertions(+), 17 deletions(-) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index da21d63f70e2..b8c9610c2313 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -364,7 +364,14 @@ void global_dirty_limits(unsigned long *pbackground,= unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thr= esh); =20 void wb_update_bandwidth(struct bdi_writeback *wb); + +/* Invoke balance dirty pages in async mode. */ +#define BDP_ASYNC 0x0001 + void balance_dirty_pages_ratelimited(struct address_space *mapping); +int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, + unsigned int flags); + bool wb_over_bg_thresh(struct bdi_writeback *wb); =20 typedef int (*writepage_t)(struct page *page, struct writeback_control *= wbc, diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 90b1998c16a1..684ab599438a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1554,8 +1554,8 @@ 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, unsigned int flags) { struct dirty_throttle_control gdtc_stor =3D { GDTC_INIT(wb) }; struct dirty_throttle_control mdtc_stor =3D { MDTC_INIT(wb, &gdtc_stor)= }; @@ -1575,6 +1575,7 @@ 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; @@ -1803,6 +1804,10 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, period, pause, start_time); + if (flags & BDP_ASYNC) { + ret =3D -EAGAIN; + break; + } __set_current_state(TASK_KILLABLE); wb->dirty_sleep =3D now; io_schedule_timeout(pause); @@ -1834,6 +1839,7 @@ 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); @@ -1854,28 +1860,18 @@ static DEFINE_PER_CPU(int, bdp_ratelimits); */ DEFINE_PER_CPU(int, dirty_throttle_leaks) =3D 0; =20 -/** - * balance_dirty_pages_ratelimited - balance dirty memory state - * @mapping: address_space which was dirtied - * - * Processes which are dirtying memory should call in here once for each= page - * which was newly dirtied. The function will periodically check the sy= stem's - * dirty state and will initiate writeback if needed. - * - * Once we're over the dirty memory limit we decrease the ratelimiting - * by a lot, to prevent individual processes from overshooting the limit - * by (ratelimit_pages) each. - */ -void balance_dirty_pages_ratelimited(struct address_space *mapping) +int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, + unsigned int flags) { struct inode *inode =3D mapping->host; struct backing_dev_info *bdi =3D inode_to_bdi(inode); struct bdi_writeback *wb =3D NULL; int ratelimit; + int ret =3D 0; int *p; =20 if (!(bdi->capabilities & BDI_CAP_WRITEBACK)) - return; + return ret; =20 if (inode_cgwb_enabled(inode)) wb =3D wb_get_create_current(bdi, GFP_KERNEL); @@ -1915,9 +1911,27 @@ void balance_dirty_pages_ratelimited(struct addres= s_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, flags); =20 wb_put(wb); + return ret; +} + +/** + * balance_dirty_pages_ratelimited - balance dirty memory state + * @mapping: address_space which was dirtied + * + * Processes which are dirtying memory should call in here once for each= page + * which was newly dirtied. The function will periodically check the sy= stem's + * dirty state and will initiate writeback if needed. + * + * Once we're over the dirty memory limit we decrease the ratelimiting + * by a lot, to prevent individual processes from overshooting the limit + * by (ratelimit_pages) each. + */ +void balance_dirty_pages_ratelimited(struct address_space *mapping) +{ + balance_dirty_pages_ratelimited_flags(mapping, 0); } EXPORT_SYMBOL(balance_dirty_pages_ratelimited); =20 --=20 2.30.2