Commit-ID: f6be8af1c95de4a46e325e728900a70ceadb52cf Gitweb: http://git.kernel.org/tip/f6be8af1c95de4a46e325e728900a70ceadb52cf Author: Chuansheng Liu <chuansheng....@intel.com> AuthorDate: Thu, 4 Sep 2014 15:17:53 +0800 Committer: Ingo Molnar <mi...@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 <l...@amacapital.net> Signed-off-by: Chuansheng Liu <chuansheng....@intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: daniel.lezc...@linaro.org Cc: r...@rjwysocki.net Cc: linux...@vger.kernel.org Cc: changcheng....@intel.com Cc: xiaoming.w...@intel.com Cc: souvik.k.chakrava...@intel.com Cc: chuansheng....@intel.com Cc: Linus Torvalds <torva...@linux-foundation.org> Link: http://lkml.kernel.org/r/1409815075-4180-1-git-send-email-chuansheng....@intel.com Signed-off-by: Ingo Molnar <mi...@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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
