Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754163AbcLOUeb (ORCPT ); Thu, 15 Dec 2016 15:34:31 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:57276 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756350AbcLOUdS (ORCPT ); Thu, 15 Dec 2016 15:33:18 -0500 Smtp-Origin-Hostprefix: devbig From: Shaohua Li Smtp-Origin-Hostname: devbig638.prn2.facebook.com To: , CC: , , , Smtp-Origin-Cluster: prn2c22 Subject: [PATCH V5 13/17] blk-throttle: ignore idle cgroup limit Date: Thu, 15 Dec 2016 12:33:04 -0800 Message-ID: X-Mailer: git-send-email 2.9.3 In-Reply-To: References: X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-12-15_14:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3252 Lines: 106 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 0218ff9..62fe72ea 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -151,8 +151,6 @@ 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]; @@ -495,8 +493,6 @@ 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_valid_limit(struct throtl_data *td) @@ -1669,9 +1665,8 @@ 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; } @@ -1718,6 +1713,26 @@ 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; @@ -1759,18 +1774,15 @@ 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; } @@ -1904,10 +1916,10 @@ 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; -- 2.9.3