From: Vincent Guittot <vincent.guittot@linaro.org>
To: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Yuyang Du <yuyang.du@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Benjamin Segall <bsegall@google.com>,
Paul Turner <pjt@google.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>
Subject: Re: [PATCH v4 1/5] sched/fair: Clean up attach_entity_load_avg()
Date: Mon, 6 Jun 2016 15:40:18 +0200 [thread overview]
Message-ID: <CAKfTPtA3bpJw_W6FsA6CULe_yjxX-bzfcuAf15ncQOUdPB187Q@mail.gmail.com> (raw)
In-Reply-To: <20160606133045.GR2658@codeblueprint.co.uk>
Hi Matt,
On 6 June 2016 at 15:30, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> On Mon, 06 Jun, at 08:20:37AM, Yuyang Du wrote:
>> attach_entity_load_avg() is called (indirectly) from:
>>
>> - switched_to_fair(): switch between classes to fair
>> - task_move_group_fair(): move between task groups
>> - enqueue_entity_load_avg(): enqueue entity
>>
>> Only in switched_to_fair() is it possible that the task's last_update_time
>> is not 0 and therefore the task needs sched avgs update, so move the task
>> sched avgs update to switched_to_fair() only. In addition, the code is
>> refactored and code comments are updated.
>>
>> No functionality change.
>>
>> Signed-off-by: Yuyang Du <yuyang.du@intel.com>
>> ---
>> kernel/sched/fair.c | 43 ++++++++++++++++++++-----------------------
>> 1 file changed, 20 insertions(+), 23 deletions(-)
>
> What about when tasks are moved between groups on CONFIG_SMP=n ?
> Doesn't this change fail to age the load in that case?
The load average stuff is only enable for SMP system but it's not used
for UP system.
To be honest, I don't know why
Vincent
next prev parent reply other threads:[~2016-06-06 13:40 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-06 0:20 [PATCH v4 0/5] sched/fair: Fix attach and detach sched avgs for task group change or sched class change Yuyang Du
2016-06-06 0:20 ` [PATCH v4 1/5] sched/fair: Clean up attach_entity_load_avg() Yuyang Du
2016-06-06 13:30 ` Matt Fleming
2016-06-06 13:40 ` Vincent Guittot [this message]
2016-06-06 14:06 ` Matt Fleming
2016-06-06 14:27 ` Peter Zijlstra
2016-06-06 0:20 ` [PATCH v4 2/5] sched/fair: Fix attaching task sched avgs twice when switching to fair or changing task group Yuyang Du
2016-06-06 9:54 ` Peter Zijlstra
2016-06-06 19:38 ` Yuyang Du
2016-06-06 12:32 ` Vincent Guittot
2016-06-06 19:05 ` Yuyang Du
2016-06-07 8:09 ` Vincent Guittot
2016-06-07 18:16 ` Yuyang Du
2016-06-06 0:20 ` [PATCH v4 3/5] sched/fair: Skip detach sched avgs for new task when changing task groups Yuyang Du
2016-06-06 9:58 ` Peter Zijlstra
2016-06-06 14:03 ` Matt Fleming
2016-06-06 19:15 ` Yuyang Du
2016-06-06 0:20 ` [PATCH v4 4/5] sched/fair: Move load and util avgs from wake_up_new_task() to sched_fork() Yuyang Du
2016-06-06 0:20 ` [PATCH v4 5/5] sched/fair: Add inline to detach_entity_load_evg() Yuyang Du
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