lkml.org 
[lkml]   [2019]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware
On Wed 25-09-19 12:40:40, Peter Zijlstra wrote:
> On Tue, Sep 24, 2019 at 03:19:39PM +0200, Michal Hocko wrote:
>
> > > The below would get rid of the PMU and workqueue warnings with no
> > > side-effects (the device isn't used for anything except sysfs).
> >
> > Hardcoding to 0 is simply wrong, if the node0 is cpuless for example...
>
> It doesn't matter.... that 0 is _never_ used. These are fake devices,
> and all we care about is getting rid of that error.

That is a very subtle and hard to review assumption. Even if this holds
now a future change might easily break this AFAIU. It also assumes that
you catch all such special devices.

I am sorry but I still do not understand why you consider this whack a
mole better then simply live with the fact that NUMA_NO_NODE is a
reality and that using the full cpu mask is a reasonable answer to that.
Anyway, I feel we are loop here so I will leave out the final decision
to you.

> If it makes you feel better we can make it -2 and have dev_to_node()
> WARN if it ever sees one.

That would help

--
Michal Hocko
SUSE Labs

\
 
 \ /
  Last update: 2019-09-25 15:27    [W:0.098 / U:4.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site