From nobody Wed Dec 24 21:51:32 2025 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5D995C618; Tue, 23 Jan 2024 10:35:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706006156; cv=none; b=XAjXUsW5W5Os5huM+o+zt12DkgJpGi0tAj2DPteCwlGfdbfwjA4urdKxdxcPmgY339k8ZJ+JTb+xzqQqVqJvBFUpz3a0ME6CUmxZSTs5/Pr/kAL6wB6vPjNciSxta5S4/soNkxM3vpJ5mig9NMFoWDNJm/kd5a7pnw3MxIwwB3w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706006156; c=relaxed/simple; bh=2cNP4Yx5S2UVM++084bf4o4tRbc7pSIPr9tRrCFa0TQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nX71XBgDqrw2/xMpiRBiHWPxett+SBrbA0SfxJZMg3DpWqyqm02RvjXaMHBBicwKMj3Frk8h0W5aATfj5Ai+Y46ncBjHaWPFTJCcrTXI44J5ygVql1vyFWVYib2P3mzMSe8DnaeymnuwU/J8FHkOeVPBXC3pfhdg1fvfaIWvSbU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4TK3QT1SSgz4f3lfn; Tue, 23 Jan 2024 18:35:45 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 778851A0232; Tue, 23 Jan 2024 18:35:51 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgA3Bg+Flq9ly6DjBg--.30161S3; Tue, 23 Jan 2024 18:35:51 +0800 (CST) From: Kemeng Shi To: willy@infradead.org, akpm@linux-foundation.org Cc: tj@kernel.org, hcochran@kernelspring.com, mszeredi@redhat.com, axboe@kernel.dk, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/5] mm: enable __wb_calc_thresh to calculate dirty background threshold Date: Wed, 24 Jan 2024 02:33:28 +0800 Message-Id: <20240123183332.876854-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20240123183332.876854-1-shikemeng@huaweicloud.com> References: <20240123183332.876854-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgA3Bg+Flq9ly6DjBg--.30161S3 X-Coremail-Antispam: 1UD129KBjvJXoWxZw4rZrWfJr45Gw1rWrWkCrg_yoWrGF47pF W3Xw17CF4UJrZ7ZrsxAFyruFWavws7JFW2q3s7Jw15tw1akryUKr12kF4vyFy5AF93JFy3 AFWYqr97XF1qyrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUB0b4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M2 8IrcIa0xkI8VA2jI8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l 84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I 8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AK xVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK 8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I 0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUsWrWDUUUU X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Content-Type: text/plain; charset="utf-8" Originally, __wb_calc_thresh always calculate wb's share of dirty throttling threshold. By getting thresh of wb_domain from caller, __wb_calc_thresh could be used for both dirty throttling and dirty background threshold. This is a preparation to correct threshold calculation of wb in cgroup. Signed-off-by: Kemeng Shi --- mm/page-writeback.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index cd4e4ae77c40..9268859722c4 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -838,13 +838,15 @@ static void mdtc_calc_avail(struct dirty_throttle_con= trol *mdtc, } =20 /** - * __wb_calc_thresh - @wb's share of dirty throttling threshold + * __wb_calc_thresh - @wb's share of dirty threshold * @dtc: dirty_throttle_context of interest + * @thresh: dirty throttling or dirty background threshold of wb_domain in= @dtc * - * Note that balance_dirty_pages() will only seriously take it as a hard l= imit - * when sleeping max_pause per page is not enough to keep the dirty pages = under - * control. For example, when the device is completely stalled due to some= error - * conditions, or when there are 1000 dd tasks writing to a slow 10MB/s US= B key. + * Note that balance_dirty_pages() will only seriously take dirty throttli= ng + * threshold as a hard limit when sleeping max_pause per page is not enough + * to keep the dirty pages under control. For example, when the device is + * completely stalled due to some error conditions, or when there are 1000 + * dd tasks writing to a slow 10MB/s USB key. * In the other normal situations, it acts more gently by throttling the t= asks * more (rather than completely block them) when the wb dirty pages go hig= h. * @@ -855,19 +857,20 @@ static void mdtc_calc_avail(struct dirty_throttle_con= trol *mdtc, * The wb's share of dirty limit will be adapting to its throughput and * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set. * - * Return: @wb's dirty limit in pages. The term "dirty" in the context of - * dirty balancing includes all PG_dirty and PG_writeback pages. + * Return: @wb's dirty limit in pages. For dirty throttling limit, the term + * "dirty" in the context of dirty balancing includes all PG_dirty and + * PG_writeback pages. */ -static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc) +static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc, + unsigned long thresh) { struct wb_domain *dom =3D dtc_dom(dtc); - unsigned long thresh =3D dtc->thresh; u64 wb_thresh; unsigned long numerator, denominator; unsigned long wb_min_ratio, wb_max_ratio; =20 /* - * Calculate this BDI's share of the thresh ratio. + * Calculate this wb's share of the thresh ratio. */ fprop_fraction_percpu(&dom->completions, dtc->wb_completions, &numerator, &denominator); @@ -887,9 +890,9 @@ static unsigned long __wb_calc_thresh(struct dirty_thro= ttle_control *dtc) =20 unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thres= h) { - struct dirty_throttle_control gdtc =3D { GDTC_INIT(wb), - .thresh =3D thresh }; - return __wb_calc_thresh(&gdtc); + struct dirty_throttle_control gdtc =3D { GDTC_INIT(wb) }; + + return __wb_calc_thresh(&gdtc, thresh); } =20 /* @@ -1636,7 +1639,7 @@ static inline void wb_dirty_limits(struct dirty_throt= tle_control *dtc) * wb_position_ratio() will let the dirtier task progress * at some rate <=3D (write_bw / 2) for bringing down wb_dirty. */ - dtc->wb_thresh =3D __wb_calc_thresh(dtc); + dtc->wb_thresh =3D __wb_calc_thresh(dtc, dtc->thresh); dtc->wb_bg_thresh =3D dtc->thresh ? div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0; =20 --=20 2.30.0