From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759388AbXJXOI2 (ORCPT ); Wed, 24 Oct 2007 10:08:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758637AbXJXOHb (ORCPT ); Wed, 24 Oct 2007 10:07:31 -0400 Received: from 75-130-111-13.dhcp.oxfr.ma.charter.com ([75.130.111.13]:49082 "EHLO novell1.haskins.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758720AbXJXOH3 (ORCPT ); Wed, 24 Oct 2007 10:07:29 -0400 From: Gregory Haskins Subject: [PATCH 3/9] RT: Clean up some of the push-rt logic To: linux-rt-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Gregory Haskins , Steven Rostedt , Dmitry Adamushko , Peter Zijlstra , Ingo Molnar , Darren Hart Date: Wed, 24 Oct 2007 09:52:48 -0400 Message-ID: <20071024135248.7960.54006.stgit@novell1.haskins.net> In-Reply-To: <20071024134431.7960.41984.stgit@novell1.haskins.net> References: <20071024134431.7960.41984.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 X-Mailing-List: linux-kernel@vger.kernel.org Get rid of the superfluous dst_cpu, move the cpu_mask inside the search function, and collapse the two redundant pick-next-rt() functions. Signed-off-by: Gregory Haskins --- kernel/sched.c | 27 ++++++++++++--------------- kernel/sched_rt.c | 44 -------------------------------------------- 2 files changed, 12 insertions(+), 59 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 821f115..de5fc1c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1471,9 +1471,10 @@ next_in_queue: * Return the highest-prio non-running RT task (if task * may run on this CPU): */ - if (!task_running(src_rq, tmp) && - cpu_isset(this_cpu, tmp->cpus_allowed)) - return tmp; + if (!task_running(src_rq, tmp)) { + if ((this_cpu == -1) || cpu_isset(this_cpu, tmp->cpus_allowed)) + return tmp; + } curr = curr->next; if (curr != head) @@ -1489,20 +1490,21 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest); #define RT_PUSH_MAX_TRIES 3 /* Will lock the rq it finds */ -static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask, - struct task_struct *task, +static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *this_rq) { struct rq *lowest_rq = NULL; - int dst_cpu = -1; int cpu; int tries; + cpumask_t cpu_mask; + + cpus_and(cpu_mask, cpu_online_map, task->cpus_allowed); for (tries = 0; tries < RT_PUSH_MAX_TRIES; tries++) { /* * Scan each rq for the lowest prio. */ - for_each_cpu_mask(cpu, *cpu_mask) { + for_each_cpu_mask(cpu, cpu_mask) { struct rq *rq = &per_cpu(runqueues, cpu); if (cpu == this_rq->cpu) @@ -1511,7 +1513,6 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask, /* We look for lowest RT prio or non-rt CPU */ if (rq->curr_prio >= MAX_RT_PRIO) { lowest_rq = rq; - dst_cpu = cpu; break; } @@ -1519,7 +1520,6 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask, if (rq->curr_prio > task->prio && (!lowest_rq || rq->curr_prio < lowest_rq->curr_prio)) { lowest_rq = rq; - dst_cpu = cpu; } } @@ -1535,7 +1535,7 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask, */ if (unlikely(task_running(this_rq, task) || task_rq(task) != this_rq || - !cpu_isset(dst_cpu, task->cpus_allowed))) { + !cpu_isset(lowest_rq->cpu, task->cpus_allowed))) { spin_unlock(&lowest_rq->lock); lowest_rq = NULL; break; @@ -1566,21 +1566,18 @@ static int push_rt_task(struct rq *this_rq) struct rq *lowest_rq; int dst_cpu; int ret = 0; - cpumask_t cpu_mask; assert_spin_locked(&this_rq->lock); - next_task = rt_next_highest_task(this_rq); + next_task = pick_rt_task(this_rq, -1); if (!next_task) return 0; - cpus_and(cpu_mask, cpu_online_map, next_task->cpus_allowed); - /* We might release this_rq lock */ get_task_struct(next_task); /* find_lock_lowest_rq locks the rq if found */ - lowest_rq = find_lock_lowest_rq(&cpu_mask, next_task, this_rq); + lowest_rq = find_lock_lowest_rq(next_task, this_rq); if (!lowest_rq) goto out; diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 546526b..9b677c1 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -96,50 +96,6 @@ static struct task_struct *pick_next_task_rt(struct rq *rq) return next; } -#ifdef CONFIG_PREEMPT_RT -static struct task_struct *rt_next_highest_task(struct rq *rq) -{ - struct rt_prio_array *array = &rq->rt.active; - struct task_struct *next; - struct list_head *queue; - int idx; - - if (likely (rq->rt_nr_running < 2)) - return NULL; - - idx = sched_find_first_bit(array->bitmap); - if (idx >= MAX_RT_PRIO) { - WARN_ON(1); /* rt_nr_running is bad */ - return NULL; - } - - queue = array->queue + idx; - next = list_entry(queue->next, struct task_struct, run_list); - if (unlikely(next != current)) - return next; - - if (queue->next->next != queue) { - /* same prio task */ - next = list_entry(queue->next->next, struct task_struct, run_list); - goto out; - } - - /* slower, but more flexible */ - idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); - if (idx >= MAX_RT_PRIO) { - WARN_ON(1); /* rt_nr_running was 2 and above! */ - return NULL; - } - - queue = array->queue + idx; - next = list_entry(queue->next, struct task_struct, run_list); - - out: - return next; - -} -#endif /* CONFIG_PREEMPT_RT */ - static void put_prev_task_rt(struct rq *rq, struct task_struct *p) { update_curr_rt(rq);