Re: [patch 00/41] cpu alloc / cpu ops v3: Optimize per cpu access

KAMEZAWA Hiroyuki
2008-05-30T06:46:54Z

On Thu, 29 May 2008 23:16:11 -0700 (PDT)
Christoph Lameter <clameter@sgi.com> wrote:

> On Thu, 29 May 2008, Andrew Morton wrote:
>
> > > No. The module subsystem has its own alloc_percpu subsystem that the
> > > cpu_alloc replaces.
> >
> > That is to support DEFINE_PER_CPU, not alloc_percpu().
>
> Right but it needs to have its own section of the percpu space from which
> it allocates the percpu segments for the modules. So it effectively
> implements an allocator.
>

Could you add a text to explain "This interface is for wise use of
pre-allocated limited area (see Documentation/xxxx). please use this only
when you need very fast access to per-cpu object and you can estimate the amount
which you finally need. If unsure, please use generic allocator."

for the moment ?

At first look, I thought of using this in memory-resource-controller but it seems
I shouldn't do so because thousands of cgroup can be used in theory...

Thanks,
-Kame