Re: [patch,v2] bdi: add a user-tunable cpu_list for the bdi flusher threads

[Jeff Moyer]

Tejun Heo <tj@xxxxxxxxxx> writes:

> Hello, Jens.
>
> On Thu, Dec 06, 2012 at 07:19:34PM +0100, Jens Axboe wrote:
>> We need to expose it. Once the binding is set from the kernel side on a
>> kernel thread, it can't be modified.
>
> That's only if kthread_bind() is used.  Caling set_cpus_allowed_ptr()
> doesn't set PF_THREAD_BOUND and userland can adjust affinity like any
> other tasks.
>
>> Binding either for performance reasons or for ensuring that we
>> explicitly don't run in some places is a very useful feature.
>
> Sure, but I think this is too specific.  Something more generic would
> be much better.  It can be as simple as generating a uevent.

I'm in favor of a more general approach.  For now, I'm still going to
push a patch that at least binds to the proper numa node.  I'll post
that after I've tested it.

Cheers,
Jeff
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/