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 E6D6FC4332F for ; Mon, 17 Oct 2022 18:16:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CC35C8E0009; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C73088E0007; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AC5BA8E0009; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 9BE928E0007 for ; Mon, 17 Oct 2022 14:16:46 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 4ECE3C0E4D for ; Mon, 17 Oct 2022 18:16:46 +0000 (UTC) X-FDA: 80031247212.15.F5675A0 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by imf08.hostedemail.com (Postfix) with ESMTP id D6A17160039 for ; Mon, 17 Oct 2022 18:16:45 +0000 (UTC) Received: by dev1180.prn1.facebook.com (Postfix, from userid 425415) id 3407B39C99C0; Mon, 17 Oct 2022 11:13:56 -0700 (PDT) From: Stefan Roesch To: kernel-team@fb.com, linux-block@vger.kernel.org, linux-mm@kvack.org Cc: shr@devkernel.io, axboe@kernel.dk, clm@meta.com, willy@infradead.org, hch@infradead.org Subject: [RFC PATCH v2 07/14] mm: add bdi_set_max_bytes() function. Date: Mon, 17 Oct 2022 11:13:30 -0700 Message-Id: <20221017181337.3884657-8-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221017181337.3884657-1-shr@devkernel.io> References: <20221017181337.3884657-1-shr@devkernel.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666030606; a=rsa-sha256; cv=none; b=q/Ps0Ci7YtJ0zJZrzOYNWjXIobaeV/TT7ZgqNwUZJDKyER0vvPQZrU18q7U9ZhaC6vvFeI BOuAGspM0M4HH4ZnFrgS7NOgsJEJa91zXSrbsAOMt6xDKGe8JNShxFYVuEYvEI6s6llvVL 32x15XjJAg4+mRBVnQuBHOyVU1jZRwQ= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf08.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666030606; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=it+iQRaOHmELQWEQlvHFdT3OewIRYM8FjrEDUznl5E0=; b=x5bDpyxueEAyPEW+NIX2PFyIUAuEcMzqQZDlhDAOjRdCWyaS+sgxPnx/6MWgEexmd8K0UL mH2h38FutIUQbfhh96P5BJzE1orpRexjfflslhRyXWeeNA3QKu9z8S43YbYEqNcC/y7Nh+ wg690z73Lr9RK2g7KyNkqPQmty2PCUs= X-Rspam-User: Authentication-Results: imf08.hostedemail.com; dkim=none; dmarc=none; spf=neutral (imf08.hostedemail.com: 66.220.144.178 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io X-Stat-Signature: 941riaffkfgoi8fk53en7zbz3cjw4us7 X-Rspamd-Queue-Id: D6A17160039 X-Rspamd-Server: rspam10 X-HE-Tag: 1666030605-959956 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: This introduces the bdi_set_max_bytes() function. The max_bytes function does not store the max_bytes value. Instead it converts the max_bytes value into the corresponding ratio value. Signed-off-by: Stefan Roesch --- include/linux/backing-dev.h | 1 + mm/page-writeback.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index cb0e66564d4d..5eb1ae3410b2 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -108,6 +108,7 @@ static inline unsigned long wb_stat_error(void) unsigned long long bdi_get_max_bytes(struct backing_dev_info *bdi); int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_rat= io); int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_rat= io); +int bdi_set_max_bytes(struct backing_dev_info *bdi, unsigned long long m= ax_bytes); int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int stri= ct_limit); =20 /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 8b8936603783..a6594ebdcbd8 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -650,6 +650,28 @@ void wb_domain_exit(struct wb_domain *dom) */ static unsigned int bdi_min_ratio; =20 +static int bdi_check_pages_limit(unsigned long pages) +{ + unsigned long max_dirty_pages =3D global_dirtyable_memory(); + + if (pages > max_dirty_pages / 2) + return -EINVAL; + + return 0; +} + +static unsigned long bdi_ratio_from_pages(unsigned long long pages) +{ + unsigned long background_thresh; + unsigned long dirty_thresh; + unsigned long ratio; + + global_dirty_limits(&background_thresh, &dirty_thresh); + ratio =3D (pages * 100 * BDI_RATIO_SCALE) / dirty_thresh; + + return ratio; +} + static unsigned long long bdi_get_bytes(unsigned int ratio) { unsigned long background_thresh; @@ -723,6 +745,21 @@ unsigned long long bdi_get_max_bytes(struct backing_= dev_info *bdi) } EXPORT_SYMBOL_GPL(bdi_get_max_bytes); =20 +int bdi_set_max_bytes(struct backing_dev_info *bdi, unsigned long long m= ax_bytes) +{ + int ret; + unsigned long pages =3D max_bytes >> PAGE_SHIFT; + unsigned long max_ratio; + + ret =3D bdi_check_pages_limit(pages); + if (ret) + return ret; + + max_ratio =3D bdi_ratio_from_pages(pages); + return __bdi_set_max_ratio(bdi, max_ratio); +} +EXPORT_SYMBOL_GPL(bdi_set_max_bytes); + int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int stri= ct_limit) { if (strict_limit > 1) --=20 2.30.2