From patchwork Thu May 26 17:38:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 12862567 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 5146EC433EF for ; Thu, 26 May 2022 17:38:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 877768D0005; Thu, 26 May 2022 13:38:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8501A8D0001; Thu, 26 May 2022 13:38:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6EB938D0005; Thu, 26 May 2022 13:38:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 61D3A8D0001 for ; Thu, 26 May 2022 13:38:58 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 31816206E4 for ; Thu, 26 May 2022 17:38:58 +0000 (UTC) X-FDA: 79508604756.25.8154A56 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf05.hostedemail.com (Postfix) with ESMTP id A7C2D10004C for ; Thu, 26 May 2022 17:38:27 +0000 (UTC) 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 24QFmeAm025608 for ; Thu, 26 May 2022 10:38:56 -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=HPjnCKp2mP5zUhzFD7orqPqCqeAUncMT3i4YP9mUBko=; b=KpyHDRhhDvaq1OanH0uX3qo9Ic9yxq89fKNKm5oxFSYLIuWIzLSZ6W0i+dLQ2enagU2c cSIE1yX+FUIV41iFtr4ZbAKT+jeuq2D/wLXWRVhvQFGwF2QjY3/2+84lGM2VuaFEf/qy 2Wu2jyjDGJltNH4GJdgvA+vumY+ItoMiUkg= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3gacgx8thc-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 26 May 2022 10:38:56 -0700 Received: from twshared24024.25.frc3.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Thu, 26 May 2022 10:38:55 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 6F159FA621D2; Thu, 26 May 2022 10:38:45 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , Subject: [PATCH v6 03/16] mm: Add balance_dirty_pages_ratelimited_flags() function Date: Thu, 26 May 2022 10:38:27 -0700 Message-ID: <20220526173840.578265-4-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220526173840.578265-1-shr@fb.com> References: <20220526173840.578265-1-shr@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: VbGUfp-1y48GvEqdevf79ITakiJoq8Hk X-Proofpoint-ORIG-GUID: VbGUfp-1y48GvEqdevf79ITakiJoq8Hk 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=2022-05-26_09,2022-05-25_02,2022-02-23_01 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: A7C2D10004C X-Rspam-User: X-Stat-Signature: ex5ba7gzaxfu8m4h7j7othpm494snai4 Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=fb.com header.s=facebook header.b=KpyHDRhh; dmarc=pass (policy=reject) header.from=fb.com; spf=none (imf05.hostedemail.com: domain of "prvs=6145f8dd45=shr@fb.com" has no SPF policy when checking 67.231.145.42) smtp.mailfrom="prvs=6145f8dd45=shr@fb.com" X-HE-Tag: 1653586707-158640 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 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 fec248ab1fec..1bddad86a4f6 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -372,7 +372,14 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); 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); typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 89dcc7d8395a..3701e813d05f 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1545,8 +1545,8 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc) * If we're over `background_thresh' then the writeback threads are woken 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 = { GDTC_INIT(wb) }; struct dirty_throttle_control mdtc_stor = { MDTC_INIT(wb, &gdtc_stor) }; @@ -1566,6 +1566,7 @@ static void balance_dirty_pages(struct bdi_writeback *wb, struct backing_dev_info *bdi = wb->bdi; bool strictlimit = bdi->capabilities & BDI_CAP_STRICTLIMIT; unsigned long start_time = jiffies; + int ret = 0; for (;;) { unsigned long now = jiffies; @@ -1794,6 +1795,10 @@ static void balance_dirty_pages(struct bdi_writeback *wb, period, pause, start_time); + if (flags & BDP_ASYNC) { + ret = -EAGAIN; + break; + } __set_current_state(TASK_KILLABLE); wb->dirty_sleep = now; io_schedule_timeout(pause); @@ -1825,6 +1830,7 @@ static void balance_dirty_pages(struct bdi_writeback *wb, if (fatal_signal_pending(current)) break; } + return ret; } static DEFINE_PER_CPU(int, bdp_ratelimits); @@ -1845,28 +1851,18 @@ static DEFINE_PER_CPU(int, bdp_ratelimits); */ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; -/** - * 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 system'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 = mapping->host; struct backing_dev_info *bdi = inode_to_bdi(inode); struct bdi_writeback *wb = NULL; int ratelimit; + int ret = 0; int *p; if (!(bdi->capabilities & BDI_CAP_WRITEBACK)) - return; + return ret; if (inode_cgwb_enabled(inode)) wb = wb_get_create_current(bdi, GFP_KERNEL); @@ -1906,9 +1902,27 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) preempt_enable(); if (unlikely(current->nr_dirtied >= ratelimit)) - balance_dirty_pages(wb, current->nr_dirtied); + balance_dirty_pages(wb, current->nr_dirtied, flags); 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 system'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);