From: tip-bot for Chuansheng Liu <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org,
torvalds@linux-foundation.org, peterz@infradead.org,
luto@amacapital.net, tglx@linutronix.de,
chuansheng.liu@intel.com
Subject: [tip:sched/core] sched: Add new API wake_up_if_idle() to wake up the idle cpu
Date: Fri, 19 Sep 2014 04:43:45 -0700 [thread overview]
Message-ID: <tip-f6be8af1c95de4a46e325e728900a70ceadb52cf@git.kernel.org> (raw)
In-Reply-To: <1409815075-4180-1-git-send-email-chuansheng.liu@intel.com>
Commit-ID: f6be8af1c95de4a46e325e728900a70ceadb52cf
Gitweb: http://git.kernel.org/tip/f6be8af1c95de4a46e325e728900a70ceadb52cf
Author: Chuansheng Liu <chuansheng.liu@intel.com>
AuthorDate: Thu, 4 Sep 2014 15:17:53 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 19 Sep 2014 12:35:14 +0200
sched: Add new API wake_up_if_idle() to wake up the idle cpu
Implementing one new API wake_up_if_idle(), which is used to
wake up the idle CPU.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: daniel.lezcano@linaro.org
Cc: rjw@rjwysocki.net
Cc: linux-pm@vger.kernel.org
Cc: changcheng.liu@intel.com
Cc: xiaoming.wang@intel.com
Cc: souvik.k.chakravarty@intel.com
Cc: chuansheng.liu@intel.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1409815075-4180-1-git-send-email-chuansheng.liu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched.h | 1 +
kernel/sched/core.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dd9eb48..82ff3d6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1024,6 +1024,7 @@ struct sched_domain_topology_level {
extern struct sched_domain_topology_level *sched_domain_topology;
extern void set_sched_topology(struct sched_domain_topology_level *tl);
+extern void wake_up_if_idle(int cpu);
#ifdef CONFIG_SCHED_DEBUG
# define SD_INIT_NAME(type) .name = #type
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 78e5c83..f7c6ed2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1634,6 +1634,25 @@ static void ttwu_queue_remote(struct task_struct *p, int cpu)
}
}
+void wake_up_if_idle(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
+
+ if (!is_idle_task(rq->curr))
+ return;
+
+ if (set_nr_if_polling(rq->idle)) {
+ trace_sched_wake_idle_without_ipi(cpu);
+ } else {
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ if (is_idle_task(rq->curr))
+ smp_send_reschedule(cpu);
+ /* Else cpu is not in idle, do nothing here */
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ }
+}
+
bool cpus_share_cache(int this_cpu, int that_cpu)
{
return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
next prev parent reply other threads:[~2014-09-19 11:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-04 7:17 [PATCH 1/3] sched: Add new API wake_up_if_idle() to wake up the idle cpu Chuansheng Liu
2014-09-04 7:17 ` [PATCH 2/3] smp: Adding new function wake_up_all_idle_cpus() Chuansheng Liu
2014-09-04 12:56 ` Daniel Lezcano
2014-09-19 11:44 ` [tip:sched/core] smp: Add new wake_up_all_idle_cpus() function tip-bot for Chuansheng Liu
2014-09-04 7:17 ` [PATCH 3/3] cpuidle: Using the wake_up_all_idle_cpus() to wake up all idle cpus Chuansheng Liu
2014-09-04 13:01 ` Daniel Lezcano
2014-09-04 13:39 ` Liu, Chuansheng
2014-09-04 15:47 ` Peter Zijlstra
2014-09-19 11:44 ` [tip:sched/core] cpuidle: Use " tip-bot for Chuansheng Liu
2014-09-04 12:53 ` [PATCH 1/3] sched: Add new API wake_up_if_idle() to wake up the idle cpu Daniel Lezcano
2014-09-04 12:59 ` Liu, Chuansheng
2014-09-19 11:43 ` tip-bot for Chuansheng Liu [this message]
2014-12-19 20:23 ` [tip:sched/core] " Andy Lutomirski
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