Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756240AbXLDVMt (ORCPT ); Tue, 4 Dec 2007 16:12:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754917AbXLDVHp (ORCPT ); Tue, 4 Dec 2007 16:07:45 -0500 Received: from 75-130-111-13.dhcp.oxfr.ma.charter.com ([75.130.111.13]:53481 "EHLO novell1.haskins.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755023AbXLDVHl (ORCPT ); Tue, 4 Dec 2007 16:07:41 -0500 From: Gregory Haskins Subject: [PATCH 15/23] Subject: SCHED - Optimize rebalancing To: mingo@elte.hu Cc: rostedt@goodmis.org, ghaskins@novell.com, linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 04 Dec 2007 15:45:41 -0500 Message-ID: <20071204204541.3567.46150.stgit@novell1.haskins.net> In-Reply-To: <20071204204236.3567.65491.stgit@novell1.haskins.net> References: <20071204204236.3567.65491.stgit@novell1.haskins.net> User-Agent: StGIT/0.12.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2641 Lines: 87 We have logic to detect whether the system has migratable tasks, but we are not using it when deciding whether to push tasks away. So we add support for considering this new information. Signed-off-by: Gregory Haskins Signed-off-by: Steven Rostedt --- kernel/sched.c | 2 ++ kernel/sched_rt.c | 10 ++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 651270e..ed031bd 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -273,6 +273,7 @@ struct rt_rq { unsigned long rt_nr_migratory; /* highest queued rt task prio */ int highest_prio; + int overloaded; }; /* @@ -6692,6 +6693,7 @@ void __init sched_init(void) rq->migration_thread = NULL; INIT_LIST_HEAD(&rq->migration_queue); rq->rt.highest_prio = MAX_RT_PRIO; + rq->rt.overloaded = 0; #endif atomic_set(&rq->nr_iowait, 0); diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 67daa66..19db3a9 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -16,6 +16,7 @@ static inline cpumask_t *rt_overload(void) } static inline void rt_set_overload(struct rq *rq) { + rq->rt.overloaded = 1; cpu_set(rq->cpu, rt_overload_mask); /* * Make sure the mask is visible before we set @@ -32,6 +33,7 @@ static inline void rt_clear_overload(struct rq *rq) /* the order here really doesn't matter */ atomic_dec(&rto_count); cpu_clear(rq->cpu, rt_overload_mask); + rq->rt.overloaded = 0; } static void update_rt_migration(struct rq *rq) @@ -446,6 +448,9 @@ static int push_rt_task(struct rq *rq) assert_spin_locked(&rq->lock); + if (!rq->rt.overloaded) + return 0; + next_task = pick_next_highest_task_rt(rq, -1); if (!next_task) return 0; @@ -673,7 +678,7 @@ static void schedule_tail_balance_rt(struct rq *rq) * the lock was owned by prev, we need to release it * first via finish_lock_switch and then reaquire it here. */ - if (unlikely(rq->rt.rt_nr_running > 1)) { + if (unlikely(rq->rt.overloaded)) { spin_lock_irq(&rq->lock); push_rt_tasks(rq); spin_unlock_irq(&rq->lock); @@ -685,7 +690,8 @@ static void wakeup_balance_rt(struct rq *rq, struct task_struct *p) { if (unlikely(rt_task(p)) && !task_running(rq, p) && - (p->prio >= rq->curr->prio)) + (p->prio >= rq->rt.highest_prio) && + rq->rt.overloaded) push_rt_tasks(rq); } -- 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/