linux-kernel - Re: [PATCH 00/30] PREEMPT_AUTO: support lazy rescheduling

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Message-ID: <87bk87c1n7.fsf@oracle.com>
Date: Thu, 22 Feb 2024 19:14:52 -0800
From: Ankur Arora <ankur.a.arora@...cle.com>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: Raghavendra K T <raghavendra.kt@....com>,
        Ankur Arora
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Subject: Re: [PATCH 00/30] PREEMPT_AUTO: support lazy rescheduling


Thomas Gleixner <tglx@...utronix.de> writes:

> On Wed, Feb 21 2024 at 22:57, Raghavendra K T wrote:
>> On 2/21/2024 10:45 PM, Thomas Gleixner wrote:
>>> On Wed, Feb 21 2024 at 17:53, Raghavendra K T wrote:
>>>> Configuration tested.
>>>> a) Base kernel (6.7),
>>>
>>> Which scheduling model is the baseline using?
>>>
>>
>> baseline is also PREEMPT_DYNAMIC with voluntary preemption
>>
>>>> b) patched with PREEMPT_AUTO voluntary preemption.
>>>> c) patched with PREEMPT_DYNAMIC voluntary preemption.
>
> Which RCU variant do you have enabled with a, b, c ?
>
> I.e. PREEMPT_RCU=?

Raghu please confirm this, but if the defaults were chosen
then we should have:

>> baseline is also PREEMPT_DYNAMIC with voluntary preemption
PREEMPT_RCU=y

>>>> b) patched with PREEMPT_AUTO voluntary preemption.

If this was built with PREEMPT_VOLUNTARY then, PREEMPT_RCU=n.
If with CONFIG_PREEMPT, PREEMPT_RCU=y.

Might be worth rerunning the tests with the other combination
as well (still with voluntary preemption).

>>>> c) patched with PREEMPT_DYNAMIC voluntary preemption.
PREEMPT_RCU=y


Thanks

--
ankur