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Subject: Re: [PATCH v4 2/4] sched/isolation: Extend nohz_full to isolate
 managed IRQs
To:     Frederic Weisbecker <frederic@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-pci@vger.kernel.org, intel-wired-lan@lists.osuosl.org,
        mtosatti@redhat.com, sassmann@redhat.com,
        jesse.brandeburg@intel.com, lihong.yang@intel.com,
        helgaas@kernel.org, jeffrey.t.kirsher@intel.com,
        jacob.e.keller@intel.com, jlelli@redhat.com, hch@infradead.org,
        bhelgaas@google.com, mike.marciniszyn@intel.com,
        dennis.dalessandro@intel.com, thomas.lendacky@amd.com,
        jiri@nvidia.com, mingo@redhat.com, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, lgoncalv@redhat.com,
        Thomas Gleixner <tglx@linutronix.de>
References: <20200928183529.471328-1-nitesh@redhat.com>
 <20200928183529.471328-3-nitesh@redhat.com>
 <20201023132505.GZ2628@hirez.programming.kicks-ass.net>
 <20201023132950.GA47962@lothringen>
From:   Nitesh Narayan Lal <nitesh@redhat.com>
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Message-ID: <804569ba-a980-a4e7-59a7-3ef4ac8660de@redhat.com>
Date:   Fri, 23 Oct 2020 09:57:53 -0400
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On 10/23/20 9:29 AM, Frederic Weisbecker wrote:
> On Fri, Oct 23, 2020 at 03:25:05PM +0200, Peter Zijlstra wrote:
>> On Mon, Sep 28, 2020 at 02:35:27PM -0400, Nitesh Narayan Lal wrote:
>>> Extend nohz_full feature set to include isolation from managed IRQS. Th=
is
>> So you say it's for managed-irqs, the feature is actually called
>> MANAGED_IRQ, but, AFAICT, it does *NOT* in fact affect managed IRQs.
>>
>> Also, as per Thomas' earlier points, managed-irqs are in fact perfectly
>> fine and don't need help at at...
>>
>>> is required specifically for setups that only uses nohz_full and still
>>> requires isolation for maintaining lower latency for the listed CPUs.
>>>
>>> Suggested-by: Frederic Weisbecker <frederic@kernel.org>
> Ah and yes there is this tag :-p
>
> So that's my bad, I really thought this thing was about managed IRQ.
> The problem is that I can't find a single documentation about them so I'm
> too clueless on that matter.

I am also confused with this terminology.
So my bad for not taking care of this.

--=20
Thanks
Nitesh


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