From patchwork Mon Apr 6 19:58:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 6164991 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 298D6BF4A6 for ; Mon, 6 Apr 2015 20:13:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4084320303 for ; Mon, 6 Apr 2015 20:13:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46ADC202EC for ; Mon, 6 Apr 2015 20:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753876AbbDFUNx (ORCPT ); Mon, 6 Apr 2015 16:13:53 -0400 Received: from mail-qk0-f172.google.com ([209.85.220.172]:33406 "EHLO mail-qk0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753417AbbDFT7u (ORCPT ); Mon, 6 Apr 2015 15:59:50 -0400 Received: by qkx62 with SMTP id 62so31082268qkx.0; Mon, 06 Apr 2015 12:59:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=ZL6D5kgJLa3cxdHns8eYEDBrJIn8hT1A9jA1KrzJelI=; b=lPsj5t/3SEra6dXu7yNrxYfZ46yxaNKQmngpK9F9nvnkCf2XWoyBfm/Mw3DrFxwMIS uPAjG5JriBe+K/1n79rgm9osinDyjDhEel3yNUPCYN0hm93PyU4PQf3XFK6Ob7Df/5bH dKJpp0jYgC8DvXaUmEhcYaec8pB853rTRO22AGz0ou23HoLK808gAJec+TMIFht1j1pC FTBdIqGEDhc/mkDPOJgI8Zsr4gnQyqB0eyGBLU3Q4MJd3Zl3sDLBmwYChGXcH66Q2kcb lkap8W6hiBPT6LbDrdQ8DnnfxoGEhY+8dbozrMsTrOPpPYtyXUgDMHAHT8IgsVu7Ve/s ehcg== X-Received: by 10.55.26.140 with SMTP id l12mr20515830qkh.32.1428350389822; Mon, 06 Apr 2015 12:59:49 -0700 (PDT) Received: from htj.duckdns.org.lan (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 z67sm3914418qgz.10.2015.04.06.12.59.48 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Apr 2015 12:59:48 -0700 (PDT) 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, Tejun Heo Subject: [PATCH 34/49] writeback: make bdi->min/max_ratio handling cgroup writeback aware Date: Mon, 6 Apr 2015 15:58:23 -0400 Message-Id: <1428350318-8215-35-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1428350318-8215-1-git-send-email-tj@kernel.org> References: <1428350318-8215-1-git-send-email-tj@kernel.org> 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 bdi->min/max_ratio are user-configurable per-bdi knobs which regulate dirty limit of each bdi. For cgroup writeback, they need to be further distributed across wb's (bdi_writeback's) belonging to the configured bdi. This patch introduces wb_min_max_ratio() which distributes bdi->min/max_ratio according to a wb's proportion in the total active bandwidth of its bdi. v2: Update wb_min_max_ratio() to fix a bug where both min and max were assigned the min value and avoid calculations when possible. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara --- mm/page-writeback.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 46 insertions(+), 4 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index ba2b83d..8755f80 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -155,6 +155,46 @@ static unsigned long writeout_period_time = 0; */ #define VM_COMPLETIONS_PERIOD_LEN (3*HZ) +#ifdef CONFIG_CGROUP_WRITEBACK + +static void wb_min_max_ratio(struct bdi_writeback *wb, + unsigned long *minp, unsigned long *maxp) +{ + unsigned long this_bw = wb->avg_write_bandwidth; + unsigned long tot_bw = atomic_long_read(&wb->bdi->tot_write_bandwidth); + unsigned long long min = wb->bdi->min_ratio; + unsigned long long max = wb->bdi->max_ratio; + + /* + * @wb may already be clean by the time control reaches here and + * the total may not include its bw. + */ + if (this_bw < tot_bw) { + if (min) { + min *= this_bw; + do_div(min, tot_bw); + } + if (max < 100) { + max *= this_bw; + do_div(max, tot_bw); + } + } + + *minp = min; + *maxp = max; +} + +#else /* CONFIG_CGROUP_WRITEBACK */ + +static void wb_min_max_ratio(struct bdi_writeback *wb, + unsigned long *minp, unsigned long *maxp) +{ + *minp = wb->bdi->min_ratio; + *maxp = wb->bdi->max_ratio; +} + +#endif /* CONFIG_CGROUP_WRITEBACK */ + /* * In a memory zone, there is a certain amount of pages we consider * available for the page cache, which is essentially the number of @@ -539,9 +579,9 @@ static unsigned long hard_dirty_limit(unsigned long thresh) */ unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty) { - struct backing_dev_info *bdi = wb->bdi; u64 wb_dirty; long numerator, denominator; + unsigned long wb_min_ratio, wb_max_ratio; /* * Calculate this BDI's share of the dirty ratio. @@ -552,9 +592,11 @@ unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty) wb_dirty *= numerator; do_div(wb_dirty, denominator); - wb_dirty += (dirty * bdi->min_ratio) / 100; - if (wb_dirty > (dirty * bdi->max_ratio) / 100) - wb_dirty = dirty * bdi->max_ratio / 100; + wb_min_max_ratio(wb, &wb_min_ratio, &wb_max_ratio); + + wb_dirty += (dirty * wb_min_ratio) / 100; + if (wb_dirty > (dirty * wb_max_ratio) / 100) + wb_dirty = dirty * wb_max_ratio / 100; return wb_dirty; }