On 1/29/21 06:23, Marcelo Tosatti wrote:
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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
