From patchwork Wed Mar 25 22:42:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 6095501 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id CE7469F318 for ; Wed, 25 Mar 2015 22:42:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DF9362035E for ; Wed, 25 Mar 2015 22:42:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F49220218 for ; Wed, 25 Mar 2015 22:42:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752418AbbCYWmZ (ORCPT ); Wed, 25 Mar 2015 18:42:25 -0400 Received: from mail-qg0-f45.google.com ([209.85.192.45]:36702 "EHLO mail-qg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261AbbCYWmX (ORCPT ); Wed, 25 Mar 2015 18:42:23 -0400 Received: by qgf60 with SMTP id 60so53727657qgf.3; Wed, 25 Mar 2015 15:42:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=DYQ9UQVvdPhr4/7tlvZBnWbnflFPRIFoOmUJdl9Zt28=; b=ABbkih2anPVDZIwCsnpl3Jr/upx6DKL5T3X5YcWOZ6l7S7GQWNCvb6vV5olmYpwcc8 3rVfVTd/FjqeWzQy3hdFk/f1RJ02WTdV91utvmdFl83NWyQ0sXcS/NMFRjqc26ME5PXa DVPwm2tLa1JiuUv778Y3fvZAhbfZNsfpwnrE7RRU402FKgi6jaYmw4HmbnrFC7dJ08JJ fnSYcTgEBJc5MwcJT7plNbQBeOKKr87DaYzCBpdkLiJs3f9Zkz1Wt3JGFspVzuLOo8FL 5WOnUjIkvOgm/UIo344eKI0kJxlAldo0xu4AKHG5KVpZT8Xgfv+1ljboS2/CD6ybM8VL +PPA== X-Received: by 10.140.236.73 with SMTP id h70mr14474787qhc.41.1427323342217; Wed, 25 Mar 2015 15:42:22 -0700 (PDT) Received: from htj.duckdns.org (207-38-238-8.c3-0.wsd-ubr1.qens-wsd.ny.cable.rcn.com. [207.38.238.8]) by mx.google.com with ESMTPSA id z18sm2364375qkz.33.2015.03.25.15.42.20 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Mar 2015 15:42:21 -0700 (PDT) Date: Wed, 25 Mar 2015 18:42:19 -0400 From: Tejun Heo To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com Subject: [PATCH v2 07/18] writeback: make __wb_calc_thresh() take dirty_throttle_control Message-ID: <20150325224219.GU3880@htj.duckdns.org> References: <1427087267-16592-1-git-send-email-tj@kernel.org> <1427087267-16592-8-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1427087267-16592-8-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From 1597de52b4281d9e14898c4f7cf314b0f2a507ea Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 25 Mar 2015 18:34:35 -0400 wb_calc_thresh() calculates wb_thresh by scaling thresh according to the wb's portion in the system-wide write bandwidth. cgroup writeback support would need to calculate wb_thresh against memcg domain too. This patch renames wb_calc_thresh() to __wb_calc_thresh() and makes it take dirty_throttle_control so that the function can later be updated to calculate against different domains according to dirty_throttle_control. wb_calc_thresh() is now a thin wrapper around __wb_calc_thresh(). v2: The original version was incorrectly scaling dtc->dirty instead of dtc->thresh. This was due to the extremely confusing function and variable names. Added a rename patch and fixed this one. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara Cc: Wu Fengguang Cc: Greg Thelen --- The review git branch has been updated accordingly. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup-writeback-backpressure-20150322 Please use the git branch for testing. I'll post v2 series once I get more feedback. Thanks. mm/page-writeback.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0fe7e60..33b1536 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -557,9 +557,8 @@ static unsigned long hard_dirty_limit(unsigned long thresh) } /** - * wb_calc_thresh - @wb's share of dirty throttling threshold - * @wb: bdi_writeback to query - * @dirty: global dirty limit in pages + * __wb_calc_thresh - @wb's share of dirty throttling threshold + * @dtc: dirty_throttle_context of interest * * Returns @wb's dirty limit in pages. The term "dirty" in the context of * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages. @@ -578,9 +577,10 @@ static unsigned long hard_dirty_limit(unsigned long thresh) * 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. */ -unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) +static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc) { struct wb_domain *dom = &global_wb_domain; + unsigned long thresh = dtc->thresh; u64 wb_thresh; long numerator, denominator; unsigned long wb_min_ratio, wb_max_ratio; @@ -588,14 +588,14 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) /* * Calculate this BDI's share of the thresh ratio. */ - fprop_fraction_percpu(&dom->completions, &wb->completions, + fprop_fraction_percpu(&dom->completions, &dtc->wb->completions, &numerator, &denominator); wb_thresh = (thresh * (100 - bdi_min_ratio)) / 100; wb_thresh *= numerator; do_div(wb_thresh, denominator); - wb_min_max_ratio(wb, &wb_min_ratio, &wb_max_ratio); + wb_min_max_ratio(dtc->wb, &wb_min_ratio, &wb_max_ratio); wb_thresh += (thresh * wb_min_ratio) / 100; if (wb_thresh > (thresh * wb_max_ratio) / 100) @@ -604,6 +604,13 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) return wb_thresh; } +unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) +{ + struct dirty_throttle_control gdtc = { GDTC_INIT(wb), + .thresh = thresh }; + return __wb_calc_thresh(&gdtc); +} + /* * setpoint - dirty 3 * f(dirty) := 1.0 + (----------------) @@ -1323,7 +1330,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc) * wb_position_ratio() will let the dirtier task progress * at some rate <= (write_bw / 2) for bringing down wb_dirty. */ - dtc->wb_thresh = wb_calc_thresh(dtc->wb, dtc->thresh); + dtc->wb_thresh = __wb_calc_thresh(dtc); dtc->wb_bg_thresh = dtc->thresh ? div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;