Re: [PATCH 3/6] cpuset: convert cpuset_attach() to use cpumask_var_t

[Li Zefan <lizf@cn.fujitsu.com>]

>>> OK, that works.
>>>
>>> Do we need to dynamically allocate cpus_attach?  Can we just do
>>>
>>> static cpumask_t cpus_attach;
>>>
>>> ?
>>>
>> Yes, it's used by cpuset_attach() only, and cpuset_attach() is called with
>> cgroup_lock() held, so it won't happen that 2 threads access cpus_attach
>> concurrently.
> 
> You misunderstand my question.  I think.
> 
> Can we allocate cpus_attach at compile time?  Completely, not
> partially.  By doing
> 
> static cpumask_t cpus_attach;
> 
> instead of
> 
> static cpumask_var_t cpus_attach;
> ...
> 	alloc_cpumask_var(&cpus_attach, GFP_KERNEL);
> 
> ?

Ah, I misunderstood. Yes a static cpumask_t works, but what Mike Travis and
Rusty is doing is to remove cpumask_t completely, and replace cpumask_t
with cpumask_var_t wherever possible.