From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net, preeti@linux.vnet.ibm.com,
nicolas.pitre@linaro.org, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org,
patches@linaro.org, lenb@kernel.org
Subject: Re: [PATCH V3 3/6] sched: idle: Get the next timer event and pass it the cpuidle framework
Date: Mon, 10 Nov 2014 16:15:50 +0100 [thread overview]
Message-ID: <5460D6A6.9070501@linaro.org> (raw)
In-Reply-To: <20141110124353.GO3337@twins.programming.kicks-ass.net>
On 11/10/2014 01:43 PM, Peter Zijlstra wrote:
> On Fri, Nov 07, 2014 at 03:31:24PM +0100, Daniel Lezcano wrote:
>> static void cpu_idle_loop(void)
>> {
>> - unsigned int latency_req;
>> + unsigned int latency_req, next_timer_event;
>>
>> while (1) {
>> /*
>> @@ -221,6 +222,9 @@ static void cpu_idle_loop(void)
>>
>> latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
>>
>> + next_timer_event =
>> + ktime_to_us(tick_nohz_get_sleep_length());
>> +
>> /*
>> * In poll mode we reenable interrupts and spin.
>> *
>> @@ -238,7 +242,8 @@ static void cpu_idle_loop(void)
>> tick_check_broadcast_expired())
>> cpu_idle_poll();
>> else
>> - cpuidle_idle_call(latency_req);
>> + cpuidle_idle_call(latency_req,
>> + next_timer_event);
>>
>> arch_cpu_idle_exit();
>> }
>
> Why do we want to query the next timer in the poll case? Afaict the
> other patches don't make use of this either.
Well, the direction I am taking when writing those cleanups is to have
something like:
"I will sleep X usec, I have Y usec latency constraints". Grouping the
latency req and the next timer allows to stick to the next changes.
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next prev parent reply other threads:[~2014-11-10 15:15 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-07 14:31 [PATCH V3 0/6] sched: idle: cpuidle: cleanups and fixes Daniel Lezcano
2014-11-07 14:31 ` [PATCH V3 1/6] sched: idle: Add a weak arch_cpu_idle_poll function Daniel Lezcano
2014-11-08 10:39 ` Preeti U Murthy
2014-11-10 12:29 ` Peter Zijlstra
2014-11-10 14:20 ` Preeti U Murthy
2014-11-10 15:17 ` Peter Zijlstra
2014-11-11 11:00 ` Preeti U Murthy
2014-11-07 14:31 ` [PATCH V3 2/6] sched: idle: cpuidle: Check the latency req before idle Daniel Lezcano
2014-11-08 10:40 ` Preeti U Murthy
2014-11-10 12:41 ` Peter Zijlstra
2014-11-10 15:12 ` Daniel Lezcano
2014-11-10 15:28 ` Peter Zijlstra
2014-11-10 15:58 ` Daniel Lezcano
2014-11-10 16:15 ` Peter Zijlstra
2014-11-10 17:19 ` Daniel Lezcano
2014-11-10 19:48 ` Peter Zijlstra
2014-11-10 22:21 ` Daniel Lezcano
2014-11-11 10:20 ` Peter Zijlstra
2014-11-12 13:53 ` Daniel Lezcano
2014-11-12 15:02 ` Peter Zijlstra
2014-11-12 17:52 ` Daniel Lezcano
2014-11-07 14:31 ` [PATCH V3 3/6] sched: idle: Get the next timer event and pass it the cpuidle framework Daniel Lezcano
2014-11-08 10:44 ` Preeti U Murthy
2014-11-10 12:43 ` Peter Zijlstra
2014-11-10 15:15 ` Daniel Lezcano [this message]
2014-11-07 14:31 ` [PATCH V3 4/6] cpuidle: idle: menu: Don't reflect when a state selection failed Daniel Lezcano
2014-11-08 10:41 ` Preeti U Murthy
2014-11-07 14:31 ` [PATCH V3 5/6] cpuidle: menu: Fix the get_typical_interval Daniel Lezcano
2014-11-07 14:31 ` [PATCH V3 6/6] cpuidle: menu: Move the update function before its declaration Daniel Lezcano
2014-11-07 14:34 ` [PATCH V3 0/6] sched: idle: cpuidle: cleanups and fixes Daniel Lezcano
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