From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Chuansheng Liu <chuansheng.liu@intel.com>,
peterz@infradead.org, luto@amacapital.net, rjw@rjwysocki.net,
mingo@redhat.com
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
changcheng.liu@intel.com, xiaoming.wang@intel.com,
souvik.k.chakravarty@intel.com
Subject: Re: [PATCH 3/3] cpuidle: Using the wake_up_all_idle_cpus() to wake up all idle cpus
Date: Thu, 04 Sep 2014 15:01:30 +0200 [thread overview]
Message-ID: <540862AA.7060907@linaro.org> (raw)
In-Reply-To: <1409815075-4180-3-git-send-email-chuansheng.liu@intel.com>
On 09/04/2014 09:17 AM, Chuansheng Liu wrote:
> Currently kick_all_cpus_sync() or smp_call_function() can not
> break the polling idle cpu immediately.
>
> Here using wake_up_all_idle_cpus() which can wake up the polling idle
> cpu quickly is much helpful for power.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
So IIUC, kick_all_cpus_sync is a broken function, right ?
Wouldn't make sense to replace all calls to kick_all_cpus by
wake_up_all_idle_cpus ? and remove this broken function ?
> Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
> ---
> drivers/cpuidle/cpuidle.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index ee9df5e..d31e04c 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -223,7 +223,7 @@ void cpuidle_uninstall_idle_handler(void)
> {
> if (enabled_devices) {
> initialized = 0;
> - kick_all_cpus_sync();
> + wake_up_all_idle_cpus();
> }
> }
>
> @@ -530,11 +530,6 @@ EXPORT_SYMBOL_GPL(cpuidle_register);
>
> #ifdef CONFIG_SMP
>
> -static void smp_callback(void *v)
> -{
> - /* we already woke the CPU up, nothing more to do */
> -}
> -
> /*
> * This function gets called when a part of the kernel has a new latency
> * requirement. This means we need to get all processors out of their C-state,
> @@ -544,7 +539,7 @@ static void smp_callback(void *v)
> static int cpuidle_latency_notify(struct notifier_block *b,
> unsigned long l, void *v)
> {
> - smp_call_function(smp_callback, NULL, 1);
> + wake_up_all_idle_cpus();
> return NOTIFY_OK;
> }
>
>
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next prev parent reply other threads:[~2014-09-04 13:01 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 [this message]
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:sched/core] " tip-bot for Chuansheng Liu
2014-12-19 20:23 ` Andy Lutomirski
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