From patchwork Wed May 11 00:16:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaohua Li X-Patchwork-Id: 9064321 Return-Path: X-Original-To: patchwork-linux-block@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 2C4089F1C3 for ; Wed, 11 May 2016 00:19:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2CD3520160 for ; Wed, 11 May 2016 00:19:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1764C20173 for ; Wed, 11 May 2016 00:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753383AbcEKATD (ORCPT ); Tue, 10 May 2016 20:19:03 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:56673 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752092AbcEKAQp (ORCPT ); Tue, 10 May 2016 20:16:45 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.11/8.16.0.11) with SMTP id u4B0FgWA017994 for ; Tue, 10 May 2016 17:16:44 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=1/oayG50nt7JMMjLXN8bytR1VxUcALWxcURTm9FVMWo=; b=S90WHoT/LT4ne4/mwxf3nGjrKLW31o3dIHgrFZQNdoJBwsKIe9+EPzXdHdqDqB6QLEb0 v6D83U9qMxsj75g5SZdQYhPl52gKTpNPohb/8GN+9h/cWWMQnfEVSXESlWojQDe0z+cz Pfonc3dBwlDGuza4qGWp82sGI33H2saByGA= Received: from mail.thefacebook.com ([199.201.64.23]) by m0089730.ppops.net with ESMTP id 22ur09gj34-3 (version=TLSv1 cipher=AES128-SHA bits=128 verify=NOT) for ; Tue, 10 May 2016 17:16:44 -0700 Received: from mx-out.facebook.com (192.168.52.123) by PRN-CHUB13.TheFacebook.com (192.168.16.23) with Microsoft SMTP Server (TLS) id 14.3.248.2; Tue, 10 May 2016 17:16:43 -0700 Received: from facebook.com (2401:db00:11:d0a2:face:0:39:0) by mx-out.facebook.com (10.212.232.59) with ESMTP id a3a9d9e0170d11e6b37b0002c991e86a-d20d8c50 for ; Tue, 10 May 2016 17:16:43 -0700 Received: by devbig084.prn1.facebook.com (Postfix, from userid 11222) id 9DA144B01785; Tue, 10 May 2016 17:16:41 -0700 (PDT) From: Shaohua Li To: , CC: , , , , Subject: [PATCH 04/10] block-throttle: add upgrade logic for LIMIT_LOW state Date: Tue, 10 May 2016 17:16:34 -0700 Message-ID: X-Mailer: git-send-email 2.8.0.rc2 In-Reply-To: References: X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-05-10_13:, , signatures=0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-8.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,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 When queue is in LIMIT_LOW state and all cgroups with low limit cross the bps/iops limitation, we will upgrade queue's state to LIMIT_HIGH/LIMIT_MAX For a cgroup hierarchy, there are two cases. Children has lower low limit than parent. Parent's low limit is meaningless. If children's bps/iops cross low limit, we can upgrade queue state. The other case is children has higher low limit than parent. Children's low limit is meaningless. As long as parent's bps/iops cross low limit, we can upgrade queue state. Signed-off-by: Shaohua Li --- block/blk-throttle.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 86 insertions(+), 4 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index bdcf1b7..df9cd13e 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -468,6 +468,7 @@ static void blk_throtl_update_valid_limit(struct throtl_data *td) td->limit_valid[LIMIT_LOW] = false; } +static void throtl_upgrade_state(struct throtl_data *td); static void throtl_pd_offline(struct blkg_policy_data *pd) { struct throtl_grp *tg = pd_to_tg(pd); @@ -479,9 +480,8 @@ static void throtl_pd_offline(struct blkg_policy_data *pd) blk_throtl_update_valid_limit(tg->td); - if (tg->td->limit_index == LIMIT_LOW && - !tg->td->limit_valid[LIMIT_LOW]) - tg->td->limit_index = LIMIT_MAX; + if (!tg->td->limit_valid[tg->td->limit_index]) + throtl_upgrade_state(tg->td); } static void throtl_pd_free(struct blkg_policy_data *pd) @@ -1087,6 +1087,8 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) return nr_disp; } +static bool throtl_can_upgrade(struct throtl_data *td, + struct throtl_grp *this_tg); /** * throtl_pending_timer_fn - timer function for service_queue->pending_timer * @arg: the throtl_service_queue being serviced @@ -1113,6 +1115,9 @@ static void throtl_pending_timer_fn(unsigned long arg) int ret; spin_lock_irq(q->queue_lock); + if (throtl_can_upgrade(td, NULL)) + throtl_upgrade_state(td); + again: parent_sq = sq->parent_sq; dispatched = false; @@ -1520,6 +1525,77 @@ static struct blkcg_policy blkcg_policy_throtl = { .pd_free_fn = throtl_pd_free, }; +static bool throtl_upgrade_check_one(struct throtl_grp *tg) +{ + struct throtl_service_queue *sq = &tg->service_queue; + + if (tg->bps[READ][LIMIT_LOW] != 0 && !sq->nr_queued[READ]) + return false; + if (tg->bps[WRITE][LIMIT_LOW] != 0 && !sq->nr_queued[WRITE]) + return false; + if (tg->iops[READ][LIMIT_LOW] != 0 && !sq->nr_queued[READ]) + return false; + if (tg->iops[WRITE][LIMIT_LOW] != 0 && !sq->nr_queued[WRITE]) + return false; + return true; +} + +static bool throtl_upgrade_check_hierarchy(struct throtl_grp *tg) +{ + if (throtl_upgrade_check_one(tg)) + return true; + while (true) { + if (!tg || (cgroup_subsys_on_dfl(io_cgrp_subsys) && + !tg_to_blkg(tg)->parent)) + return false; + if (throtl_upgrade_check_one(tg)) + return true; + tg = sq_to_tg(tg->service_queue.parent_sq); + } + return false; +} + +static bool throtl_can_upgrade(struct throtl_data *td, + struct throtl_grp *this_tg) +{ + struct cgroup_subsys_state *pos_css; + struct blkcg_gq *blkg; + + if (td->limit_index != LIMIT_LOW) + return false; + + blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { + struct throtl_grp *tg = blkg_to_tg(blkg); + + if (tg == this_tg) + continue; + if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children)) + continue; + if (!throtl_upgrade_check_hierarchy(tg)) + return false; + } + return true; +} + +static void throtl_upgrade_state(struct throtl_data *td) +{ + struct cgroup_subsys_state *pos_css; + struct blkcg_gq *blkg; + + td->limit_index = LIMIT_MAX; + blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { + struct throtl_grp *tg = blkg_to_tg(blkg); + struct throtl_service_queue *sq = &tg->service_queue; + + tg->disptime = jiffies - 1; + throtl_select_dispatch(sq); + throtl_schedule_next_dispatch(sq, false); + } + throtl_select_dispatch(&td->service_queue); + throtl_schedule_next_dispatch(&td->service_queue, false); + queue_work(kthrotld_workqueue, &td->dispatch_work); +} + bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, struct bio *bio) { @@ -1542,14 +1618,20 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, sq = &tg->service_queue; +again: while (true) { /* throtl is FIFO - if bios are already queued, should queue */ if (sq->nr_queued[rw]) break; /* if above limits, break to queue */ - if (!tg_may_dispatch(tg, bio, NULL)) + if (!tg_may_dispatch(tg, bio, NULL)) { + if (throtl_can_upgrade(tg->td, tg)) { + throtl_upgrade_state(tg->td); + goto again; + } break; + } /* within limits, let's charge and dispatch directly */ throtl_charge_bio(tg, bio);