Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754402Ab1EGGc7 (ORCPT ); Sat, 7 May 2011 02:32:59 -0400 Received: from smtp-out.google.com ([216.239.44.51]:1507 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753452Ab1EGGcm (ORCPT ); Sat, 7 May 2011 02:32:42 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:user-agent:date:from:to:cc:subject:references:content-disposition; b=LngCwS/JCQU2HxfmXxr3QFVSWZ7Mo9oGRt7OGjhOMpA9TxgUW3029U4mcxfx7Yumy GzqYQTatI+vKbiKN3V0+w== Message-Id: <20110503092904.895444153@google.com> User-Agent: quilt/0.48-1 Date: Tue, 03 May 2011 02:28:51 -0700 From: Paul Turner To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Bharata B Rao , Dhaval Giani , Balbir Singh , Vaidyanathan Srinivasan , Srivatsa Vaddagiri , Kamalesh Babulal , Ingo Molnar , Pavel Emelyanov Subject: [patch 05/15] sched: add a timer to handle CFS bandwidth refresh References: <20110503092846.022272244@google.com> Content-Disposition: inline; filename=sched-bwc-bandwidth_timers.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5190 Lines: 189 This patch adds a per-task_group timer which handles the refresh of the global CFS bandwidth pool. Since the RT pool is using a similar timer there's some small refactoring to share this support. Signed-off-by: Paul Turner --- kernel/sched.c | 87 ++++++++++++++++++++++++++++++++++++++++------------ kernel/sched_fair.c | 9 +++++ 2 files changed, 77 insertions(+), 19 deletions(-) Index: tip/kernel/sched.c =================================================================== --- tip.orig/kernel/sched.c +++ tip/kernel/sched.c @@ -193,10 +193,28 @@ static inline int rt_bandwidth_enabled(v return sysctl_sched_rt_runtime >= 0; } -static void start_rt_bandwidth(struct rt_bandwidth *rt_b) +static void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) { - ktime_t now; + unsigned long delta; + ktime_t soft, hard, now; + + for (;;) { + if (hrtimer_active(period_timer)) + break; + + now = hrtimer_cb_get_time(period_timer); + hrtimer_forward(period_timer, now, period); + soft = hrtimer_get_softexpires(period_timer); + hard = hrtimer_get_expires(period_timer); + delta = ktime_to_ns(ktime_sub(hard, soft)); + __hrtimer_start_range_ns(period_timer, soft, delta, + HRTIMER_MODE_ABS_PINNED, 0); + } +} + +static void start_rt_bandwidth(struct rt_bandwidth *rt_b) +{ if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) return; @@ -204,22 +222,7 @@ static void start_rt_bandwidth(struct rt return; raw_spin_lock(&rt_b->rt_runtime_lock); - for (;;) { - unsigned long delta; - ktime_t soft, hard; - - if (hrtimer_active(&rt_b->rt_period_timer)) - break; - - now = hrtimer_cb_get_time(&rt_b->rt_period_timer); - hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); - - soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); - hard = hrtimer_get_expires(&rt_b->rt_period_timer); - delta = ktime_to_ns(ktime_sub(hard, soft)); - __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, - HRTIMER_MODE_ABS_PINNED, 0); - } + start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); raw_spin_unlock(&rt_b->rt_runtime_lock); } @@ -250,6 +253,9 @@ struct cfs_bandwidth { ktime_t period; u64 quota; s64 hierarchal_quota; + + int idle; + struct hrtimer period_timer; #endif }; @@ -394,12 +400,38 @@ static inline struct cfs_bandwidth *tg_c #ifdef CONFIG_CFS_BANDWIDTH static inline u64 default_cfs_period(void); +static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun); + +static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) +{ + struct cfs_bandwidth *cfs_b = + container_of(timer, struct cfs_bandwidth, period_timer); + ktime_t now; + int overrun; + int idle = 0; + + for (;;) { + now = hrtimer_cb_get_time(timer); + overrun = hrtimer_forward(timer, now, cfs_b->period); + + if (!overrun) + break; + + idle = do_sched_cfs_period_timer(cfs_b, overrun); + } + + return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; +} static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) { raw_spin_lock_init(&cfs_b->lock); cfs_b->quota = RUNTIME_INF; cfs_b->period = ns_to_ktime(default_cfs_period()); + + hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + cfs_b->period_timer.function = sched_cfs_period_timer; + } static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) @@ -411,8 +443,25 @@ static void init_cfs_rq_runtime(struct c cfs_rq->runtime_enabled = 1; } +static void start_cfs_bandwidth(struct cfs_rq *cfs_rq) +{ + struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); + + if (cfs_b->quota == RUNTIME_INF) + return; + + if (hrtimer_active(&cfs_b->period_timer)) + return; + + raw_spin_lock(&cfs_b->lock); + start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); + raw_spin_unlock(&cfs_b->lock); +} + static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) -{} +{ + hrtimer_cancel(&cfs_b->period_timer); +} #else #ifdef CONFIG_FAIR_GROUP_SCHED static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} Index: tip/kernel/sched_fair.c =================================================================== --- tip.orig/kernel/sched_fair.c +++ tip/kernel/sched_fair.c @@ -1003,6 +1003,8 @@ enqueue_entity(struct cfs_rq *cfs_rq, st if (cfs_rq->nr_running == 1) list_add_leaf_cfs_rq(cfs_rq); + + start_cfs_bandwidth(cfs_rq); } static void __clear_buddies_last(struct sched_entity *se) @@ -1220,6 +1222,8 @@ static void put_prev_entity(struct cfs_r update_stats_wait_start(cfs_rq, prev); /* Put 'current' back into the tree. */ __enqueue_entity(cfs_rq, prev); + + start_cfs_bandwidth(cfs_rq); } cfs_rq->curr = NULL; } @@ -1272,6 +1276,11 @@ static inline u64 default_cfs_period(voi { return 500000000ULL; } + +static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) +{ + return 1; +} #endif /************************************************** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/