From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC 2/6] sched: add a new SD SHARE_POWERLINE flag for sched_domain
Date: Fri, 2 Nov 2012 15:57:10 +0530 [thread overview]
Message-ID: <50939FFE.9020401@ti.com> (raw)
In-Reply-To: <CAKfTPtB4CBVZDLeRsqENUgZuefpG8+7g-oyPRMyY5J2iRJuEOA@mail.gmail.com>
On Monday 29 October 2012 03:20 PM, Vincent Guittot wrote:
> It looks like i need to describe more what
>
> On 29 October 2012 10:40, Vincent Guittot <vincent.guittot@linaro•org> wrote:
>> On 24 October 2012 17:17, Santosh Shilimkar <santosh.shilimkar@ti•com> wrote:
>>> Vincent,
>>>
>>> Few comments/questions.
>>>
>>>
>>> On Sunday 07 October 2012 01:13 PM, Vincent Guittot wrote:
>>>>
>>>> This new flag SD SHARE_POWERLINE reflects the sharing of the power rail
>>>> between the members of a domain. As this is the current assumption of the
>>>> scheduler, the flag is added to all sched_domain
>>>>
>>>> Signed-off-by: Vincent Guittot <vincent.guittot@linaro•org>
>>>> ---
>>>> arch/ia64/include/asm/topology.h | 1 +
>>>> arch/tile/include/asm/topology.h | 1 +
>>>> include/linux/sched.h | 1 +
>>>> include/linux/topology.h | 3 +++
>>>> kernel/sched/core.c | 5 +++++
>>>> 5 files changed, 11 insertions(+)
>>>>
>>>> diff --git a/arch/ia64/include/asm/topology.h
>>>> b/arch/ia64/include/asm/topology.h
>>>> index a2496e4..065c720 100644
>>>> --- a/arch/ia64/include/asm/topology.h
>>>> +++ b/arch/ia64/include/asm/topology.h
>>>> @@ -65,6 +65,7 @@ void build_cpu_to_node_map(void);
>>>> | SD_BALANCE_EXEC \
>>>> | SD_BALANCE_FORK \
>>>> | SD_WAKE_AFFINE, \
>>>> + | arch_sd_share_power_line() \
>>>> .last_balance = jiffies, \
>>>> .balance_interval = 1, \
>>>> .nr_balance_failed = 0, \
>>>> diff --git a/arch/tile/include/asm/topology.h
>>>> b/arch/tile/include/asm/topology.h
>>>> index 7a7ce39..d39ed0b 100644
>>>> --- a/arch/tile/include/asm/topology.h
>>>> +++ b/arch/tile/include/asm/topology.h
>>>> @@ -72,6 +72,7 @@ static inline const struct cpumask *cpumask_of_node(int
>>>> node)
>>>> | 0*SD_PREFER_LOCAL \
>>>> | 0*SD_SHARE_CPUPOWER \
>>>> | 0*SD_SHARE_PKG_RESOURCES \
>>>> + | arch_sd_share_power_line() \
>>>> | 0*SD_SERIALIZE \
>>>> , \
>>>> .last_balance = jiffies, \
>>>> diff --git a/include/linux/sched.h b/include/linux/sched.h
>>>> index 4786b20..74f2daf 100644
>>>> --- a/include/linux/sched.h
>>>> +++ b/include/linux/sched.h
>>>> @@ -862,6 +862,7 @@ enum cpu_idle_type {
>>>> #define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU
>>>> */
>>>> #define SD_PREFER_LOCAL 0x0040 /* Prefer to keep tasks
>>>> local to this domain */
>>>> #define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power
>>>> */
>>>> +#define SD_SHARE_POWERLINE 0x0100 /* Domain members share power
>>>> domain */
>>>
>>> If you ignore the current use of SD_SHARE_CPUPOWER, isn't the meaning of
>>> CPUPOWER and POWERLINE is same here. Just trying to understand the clear
>>> meaning of this new flag. Have you not considered SD_SHARE_CPUPOWER
>>> because it is being used for cpu_power and needs at least minimum two
>>> domains ? SD_PACKING would have been probably more appropriate based
>>> on the way it is being used in further series.
>>
>> CPUPOWER reflects the share of hw ressources between cores like for
>> hyper threading. POWERLINE describes the fact that cores are sharing
>> the same power line amore precisely the powergate.
>
> Sorry, the mail has been sent too early while I was writing it
>
> CPUPOWER reflects the share of hw ressources between cores like for
> hyper threading. POWERLINE describes the fact that cores are sharing
> the same power line and more precisely the same power gating. It looks
> like I need to describe more precisely what i would mean with
> SHARE_POWERLINE.
>
Yes. More description will help. I see bit of overlap POWERLINE
flag with SD_SHARE_CPUPOWER and SD_SHARE_PKG_RESOURCES and hence
the questions.
> I don't want to use PACKING because it's more a behavior than a
> feature. If cores can power gate independently (!SD_SHARE_POWERLINE),
> packing small tasks is one interesting behavior but it may be not the
> only one. I want to make a difference between the HW configuration and
> the behavior we want to have above it
>
Fair enough. Thanks for clarification.
Regards,
Santosh
next prev parent reply other threads:[~2012-11-02 10:27 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-07 7:43 [RFC 0/6] sched: packing small tasks Vincent Guittot
2012-10-07 7:43 ` [RFC 1/6] Revert "sched: introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" Vincent Guittot
2012-10-07 7:43 ` [RFC 2/6] sched: add a new SD SHARE_POWERLINE flag for sched_domain Vincent Guittot
2012-10-24 15:17 ` Santosh Shilimkar
2012-10-29 9:40 ` Vincent Guittot
2012-10-29 9:50 ` Vincent Guittot
2012-11-02 10:27 ` Santosh Shilimkar [this message]
2012-10-07 7:43 ` [RFC 3/6] sched: pack small tasks Vincent Guittot
2012-10-24 15:20 ` Santosh Shilimkar
2012-10-29 13:12 ` Vincent Guittot
2012-11-02 10:53 ` Santosh Shilimkar
2012-11-09 16:46 ` Morten Rasmussen
2012-11-12 13:13 ` Vincent Guittot
2012-11-12 9:30 ` Vincent Guittot
2012-11-09 17:13 ` Morten Rasmussen
2012-11-12 13:51 ` Vincent Guittot
2012-11-20 14:28 ` Morten Rasmussen
2012-11-20 16:59 ` Vincent Guittot
2012-10-07 7:43 ` [RFC 4/6] sched: secure access to other CPU statistics Vincent Guittot
2012-10-24 15:21 ` Santosh Shilimkar
2012-10-29 13:18 ` Vincent Guittot
2012-10-07 7:43 ` [RFC 5/6] sched: pack the idle load balance Vincent Guittot
2012-10-24 15:21 ` Santosh Shilimkar
2012-10-29 13:27 ` Vincent Guittot
2012-11-02 10:59 ` Santosh Shilimkar
2012-10-07 7:43 ` [RFC 6/6] ARM: sched: clear SD_SHARE_POWERLINE Vincent Guittot
2012-10-24 15:21 ` Santosh Shilimkar
2012-10-29 13:28 ` Vincent Guittot
2012-11-02 11:00 ` Santosh Shilimkar
2012-11-12 8:23 ` Vincent Guittot
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