From: Alex Belits <abelits@marvell.com>
To: Marcelo Tosatti <mtosatti@redhat.com>,
Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Robin Murphy <robin.murphy@arm.com>,
<linux-kernel@vger.kernel.org>, <linux-api@vger.kernel.org>,
<frederic@kernel.org>, <juri.lelli@redhat.com>,
<bhelgaas@google.com>, <linux-pci@vger.kernel.org>,
<rostedt@goodmis.org>, <mingo@kernel.org>, <peterz@infradead.org>,
<davem@davemloft.net>, <akpm@linux-foundation.org>,
<sfr@canb.auug.org.au>, <stephen@networkplumber.org>,
<rppt@linux.vnet.ibm.com>, <jinyuqi@huawei.com>,
<zhangshaokun@hisilicon.com>
Subject: Re: [EXT] Re: [Patch v4 1/3] lib: Restrict cpumask_local_spread to houskeeping CPUs
Date: Fri, 29 Jan 2021 09:34:42 -0800 [thread overview]
Message-ID: <a5132281-53e8-c75e-8085-7a44fa805625@marvell.com> (raw)
In-Reply-To: <20210129142356.GB40876@fuller.cnet>
On 1/29/21 06:23, Marcelo Tosatti wrote:
> External Email
>
> ----------------------------------------------------------------------
> On Fri, Jan 29, 2021 at 08:55:20AM -0500, Nitesh Narayan Lal wrote:
>>
>> On 1/28/21 3:01 PM, Thomas Gleixner wrote:
>>> On Thu, Jan 28 2021 at 13:59, Marcelo Tosatti wrote:
>>>>> The whole pile wants to be reverted. It's simply broken in several ways.
>>>> I was asking for your comments on interaction with CPU hotplug :-)
>>> Which I answered in an seperate mail :)
>>>
>>>> So housekeeping_cpumask has multiple meanings. In this case:
>>> ...
>>>
>>>> So as long as the meaning of the flags are respected, seems
>>>> alright.
>>> Yes. Stuff like the managed interrupts preference for housekeeping CPUs
>>> when a affinity mask spawns housekeeping and isolated is perfectly
>>> fine. It's well thought out and has no limitations.
>>>
>>>> Nitesh, is there anything preventing this from being fixed
>>>> in userspace ? (as Thomas suggested previously).
>>> Everything with is not managed can be steered by user space.
>>>
>>> Thanks,
>>>
>>> tglx
>>>
>>
>> So, I think the conclusion here would be to revert the change made in
>> cpumask_local_spread via the patch:
>> - lib: Restrict cpumask_local_spread to housekeeping CPUs
>>
>> Also, a similar case can be made for the rps patch that went in with
>> this:
>> - net: Restrict receive packets queuing to housekeeping CPUs
>
> Yes, this is the userspace solution:
>
> https://lkml.org/lkml/2021/1/22/815
>
> Should have a kernel document with this info and examples
> (the network queue configuration as well). Will
> send something.
>
>> + net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
>>
>> I am not sure about the PCI patch as I don't think we can control that from
>> the userspace or maybe I am wrong?
>
> You mean "lib: Restrict cpumask_local_spread to housekeeping CPUs" ?
>
If we want to do it from userspace, we should have something that
triggers it in userspace. Should we use udev for this purpose?
--
Alex
next prev parent reply other threads:[~2021-01-29 17:41 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 22:34 [PATCH v4 0/3] Preventing job distribution to isolated CPUs Nitesh Narayan Lal
2020-06-25 22:34 ` [Patch v4 1/3] lib: Restrict cpumask_local_spread to houskeeping CPUs Nitesh Narayan Lal
2020-06-29 16:11 ` Nitesh Narayan Lal
2020-07-01 0:32 ` Andrew Morton
2020-07-01 0:47 ` Nitesh Narayan Lal
2021-01-27 11:57 ` Robin Murphy
2021-01-27 12:19 ` Marcelo Tosatti
2021-01-27 12:36 ` Robin Murphy
2021-01-27 13:09 ` Marcelo Tosatti
2021-01-27 13:49 ` Robin Murphy
2021-01-27 14:16 ` Nitesh Narayan Lal
2021-01-28 15:56 ` Thomas Gleixner
2021-01-28 16:33 ` Marcelo Tosatti
[not found] ` <02ac9d85-7ddd-96da-1252-4663feea7c9f@marvell.com>
2021-02-01 17:50 ` [EXT] " Marcelo Tosatti
2021-01-28 16:02 ` Thomas Gleixner
2021-01-28 16:59 ` Marcelo Tosatti
2021-01-28 17:35 ` Nitesh Narayan Lal
2021-01-28 20:01 ` Thomas Gleixner
[not found] ` <d2a4dc97-a9ed-e0e7-3b9c-c56ae46f6608@redhat.com>
[not found] ` <20210129142356.GB40876@fuller.cnet>
2021-01-29 17:34 ` Alex Belits [this message]
[not found] ` <18584612-868c-0f88-5de2-dc93c8638816@redhat.com>
2021-02-05 19:56 ` Thomas Gleixner
2021-02-04 18:15 ` Marcelo Tosatti
2021-02-04 18:47 ` Nitesh Narayan Lal
2021-02-04 19:06 ` Marcelo Tosatti
2021-02-04 19:17 ` Nitesh Narayan Lal
2021-02-05 22:23 ` Thomas Gleixner
2021-02-05 22:26 ` Thomas Gleixner
2021-02-07 0:43 ` Nitesh Narayan Lal
2021-02-11 15:55 ` Nitesh Narayan Lal
2021-03-04 18:15 ` Nitesh Narayan Lal
[not found] ` <faa8d84e-db67-7fbe-891e-f4987f106b20@marvell.com>
2021-03-04 23:23 ` [EXT] " Nitesh Narayan Lal
2021-04-06 17:22 ` Jesse Brandeburg
2021-04-07 15:18 ` Nitesh Narayan Lal
2021-04-08 18:49 ` Nitesh Narayan Lal
2021-04-14 16:11 ` Jesse Brandeburg
2021-04-15 22:11 ` Nitesh Narayan Lal
2021-04-29 21:44 ` Nitesh Lal
2021-04-30 1:48 ` Jesse Brandeburg
2021-04-30 13:10 ` Nitesh Lal
2021-04-30 7:10 ` Thomas Gleixner
2021-04-30 16:14 ` Nitesh Lal
2021-04-30 18:21 ` Thomas Gleixner
2021-04-30 21:07 ` Nitesh Lal
2021-05-01 2:21 ` Jesse Brandeburg
2021-05-03 13:15 ` Nitesh Lal
2020-06-25 22:34 ` [Patch v4 2/3] PCI: Restrict probe functions to housekeeping CPUs Nitesh Narayan Lal
2020-06-25 22:34 ` [Patch v4 3/3] net: Restrict receive packets queuing " Nitesh Narayan Lal
2020-06-26 11:14 ` Peter Zijlstra
2020-06-26 17:20 ` David Miller
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