Re: [PATCH] use for_each_cpu

Andrew Morton
2004-08-01T07:48:49Z

Anton Blanchard <anton@samba.org> wrote:
>
>
> > > The per cpu schedule counters need to be summed up over all possible cpus.
> > > When testing hotplug cpu remove I saw the sum of the online cpu count
> > > for nr_uninterruptible go negative which made the load average go nuts.
> >
> > I think the preferred approach here is to transfer the count over to the
> > current CPU in the CPU_DEAD handler.
>
> They only look to be called out of proc, and once every 5 seconds for
> loadaverage calculations.

OK.

> Is it worth adding complexity to the cpu
> notifiers vs just using for_each_cpu?

yup ;) It's only six lines, and it follows the same pattern as is used in,
say, page_alloc_cpu_notify(). Doing the same thing the same way in
multiple places is to be preferred, yes?