From patchwork Sun Jan 15 03:42:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaohua Li X-Patchwork-Id: 9517245 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4D4C5607DA for ; Sun, 15 Jan 2017 03:44:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 42AA72842C for ; Sun, 15 Jan 2017 03:44:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 300AF28440; Sun, 15 Jan 2017 03:44:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B4EFB28440 for ; Sun, 15 Jan 2017 03:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751052AbdAODnH (ORCPT ); Sat, 14 Jan 2017 22:43:07 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:33976 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750795AbdAODmk (ORCPT ); Sat, 14 Jan 2017 22:42:40 -0500 Received: from pps.filterd (m0001255.ppops.net [127.0.0.1]) by mx0b-00082601.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v0F3gJAi004922 for ; Sat, 14 Jan 2017 19:42:40 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=yV+hyZfOOpsCbvVHULkPyg41w17vWgBouUNorrMGoS4=; b=SKznwWfKdheBJGBn/SDkLuJlXA5OiLAOJZhosCrRWkf7PyuacTzwSXDiGMXrNMPAUlJU nNHQ2nxw0M1q649XdaIDeWkK5uhv7MMfiUQMRhdlRnInF/HLOZKEfMLIbm3x+bHFBxw7 FYh3DbwnUA8oRZD8yVFJUs1Y1BPwJjvJFqI= Received: from mail.thefacebook.com ([199.201.64.23]) by mx0b-00082601.pphosted.com with ESMTP id 27ygp5hj23-9 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sat, 14 Jan 2017 19:42:40 -0800 Received: from mx-out.facebook.com (192.168.52.123) by PRN-CHUB11.TheFacebook.com (192.168.16.21) with Microsoft SMTP Server (TLS) id 14.3.294.0; Sat, 14 Jan 2017 19:42:36 -0800 Received: from facebook.com (2401:db00:21:603d:face:0:19:0) by mx-out.facebook.com (10.103.99.99) with ESMTP id a7b62ff8dad411e68bf20002c9dfb610-2c1f2a50 for ; Sat, 14 Jan 2017 19:42:36 -0800 Received: by devbig638.prn2.facebook.com (Postfix, from userid 11222) id 36CE04363473; Sat, 14 Jan 2017 19:42:36 -0800 (PST) Smtp-Origin-Hostprefix: devbig From: Shaohua Li Smtp-Origin-Hostname: devbig638.prn2.facebook.com To: , CC: , , , Smtp-Origin-Cluster: prn2c22 Subject: [PATCH V6 14/18] blk-throttle: ignore idle cgroup limit Date: Sat, 14 Jan 2017 19:42:31 -0800 Message-ID: <7adf686572e185bd29e5e595851f80873751a464.1484451062.git.shli@fb.com> X-Mailer: git-send-email 2.9.3 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=2017-01-15_03:, , signatures=0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Last patch introduces a way to detect idle cgroup. We use it to make upgrade/downgrade decision. And the new algorithm can detect completely idle cgroup too, so we can delete the corresponding code. Signed-off-by: Shaohua Li --- block/blk-throttle.c | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 88c0d1e..cf8d386 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -152,8 +152,6 @@ struct throtl_grp { unsigned long last_check_time; - unsigned long last_dispatch_time[2]; - /* When did we start a new slice */ unsigned long slice_start[2]; unsigned long slice_end[2]; @@ -508,8 +506,6 @@ static void throtl_pd_online(struct blkg_policy_data *pd) * Update has_rules[] after a new group is brought online. */ tg_update_has_rules(tg); - tg->last_dispatch_time[READ] = jiffies; - tg->last_dispatch_time[WRITE] = jiffies; } static void blk_throtl_update_limit_valid(struct throtl_data *td) @@ -1704,9 +1700,8 @@ static bool throtl_tg_can_upgrade(struct throtl_grp *tg) return true; if (time_after_eq(jiffies, - tg->last_dispatch_time[READ] + tg->td->throtl_slice) && - time_after_eq(jiffies, - tg->last_dispatch_time[WRITE] + tg->td->throtl_slice)) + tg_last_low_overflow_time(tg) + tg->td->throtl_slice) && + throtl_tg_is_idle(tg)) return true; return false; } @@ -1752,6 +1747,26 @@ static bool throtl_can_upgrade(struct throtl_data *td, return true; } +static void throtl_upgrade_check(struct throtl_grp *tg) +{ + unsigned long now = jiffies; + + if (tg->td->limit_index != LIMIT_LOW) + return; + + if (time_after(tg->last_check_time + tg->td->throtl_slice, now)) + return; + + tg->last_check_time = now; + + if (!time_after_eq(now, + __tg_last_low_overflow_time(tg) + tg->td->throtl_slice)) + return; + + if (throtl_can_upgrade(tg->td, NULL)) + throtl_upgrade_state(tg->td); +} + static void throtl_upgrade_state(struct throtl_data *td) { struct cgroup_subsys_state *pos_css; @@ -1793,18 +1808,15 @@ static bool throtl_tg_can_downgrade(struct throtl_grp *tg) struct throtl_data *td = tg->td; unsigned long now = jiffies; - if (time_after_eq(now, tg->last_dispatch_time[READ] + - td->throtl_slice) && - time_after_eq(now, tg->last_dispatch_time[WRITE] + - td->throtl_slice)) - return false; /* * If cgroup is below low limit, consider downgrade and throttle other * cgroups */ if (time_after_eq(now, td->low_upgrade_time + td->throtl_slice) && time_after_eq(now, tg_last_low_overflow_time(tg) + - td->throtl_slice)) + td->throtl_slice) && + (!throtl_tg_is_idle(tg) || + !list_empty(&tg_to_blkg(tg)->blkcg->css.children))) return true; return false; } @@ -1926,10 +1938,10 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, again: while (true) { - tg->last_dispatch_time[rw] = jiffies; if (tg->last_low_overflow_time[rw] == 0) tg->last_low_overflow_time[rw] = jiffies; throtl_downgrade_check(tg); + throtl_upgrade_check(tg); /* throtl is FIFO - if bios are already queued, should queue */ if (sq->nr_queued[rw]) break;