Re: [PATCH V2 Resend 3/4] workqueue: Schedule work on non-idle cpu instead of current one

On Mon, 2013-01-07 at 23:29 +0530, Viresh Kumar wrote:

quoted

By default, I would suggest for cache locality,
that we try to keep it on the same CPU. But if there's a better CPU to
run on, it runs there.

That would break our intention behind this routine. We should run
it on a cpu which we think is the best one for it power/performance wise.

If you are running on a big.Little box sure. But for normal (read x86 ;)
systems, it should probably stay on the current CPU.

So, i would like to call the sched_select_cpu() routine from this routine to
get the suggested cpu.

Does the caller need to know? Or if you have a big.LITTLE setup, it
should just work automagically?

This routine would however would see more changes later to optimize it
more.

quoted

Also, we could still add a debug option that
makes it always run on other CPUs to slap developers that don't read.

I don't think we need it :(
It would be a new API, with zero existing users. And so, whomsoever uses
it, should know what exactly he is doing :)

Heh, you don't know kernel developers well do you? ;-)

Once a new API is added to the kernel tree, it quickly becomes
(mis)used.

-- Steve