Re: [PATCH v3] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512

[Christoph Lameter (Ampere)]

On Fri, 8 Mar 2024, Marek Szyprowski wrote:

> > > It looks that cpufreq-dt and/or opp drivers needs some adjustments
> > > related with this change.
> > That's strange. Is this with defconfig? I wonder whether NR_CPUS being
> > larger caused the issue with this specific code. Otherwise
> > CPUMASK_OFFSTACK may not work that well on arm64.

cpumask handling must use the accessor functions provided in 
include/linux/cpumask.h for declaring and accessing cpumasks. It is likely 
related to the driver opencoding one of the accessors.

I.e. you must use alloc_cpumask_var() and not allocate yourself on the 
stack.