Subject: Re: [PATCH 1/3] powernv:idle: Use correct IDLE_THREAD_BITS in POWER8/9

From: Gautham R Shenoy <[email-masked]>
Date: Thu, 13 Apr 2017 17:05:13 +0530

On Thu, Apr 13, 2017 at 08:00:47PM +1000, Michael Ellerman wrote:
> Michael Neuling <[email-masked]> writes:
> 
> > On Wed, 2017-04-12 at 17:16 +0530, Gautham R. Shenoy wrote:
> >> From: "Gautham R. Shenoy" <[email-masked]>
> >> 
> >> This patch ensures that POWER8 and POWER9 processors use the correct
> >> value of IDLE_THREAD_BITS as POWER8 has 8 threads per core and hence
> >> the IDLE_THREAD_BITS should be 0xFF while POWER9 has only 4 threads
> >> per core and hence the IDLE_THREAD_BITS should be 0xF.
> >
> > Why don't we derive this from the device tree rather than hard wiring it per cpu
> > type?
> 
> Right.
> 
> In fact we already have threads_per_core which is exactly that.

Ok. I will convert IDLE_THREAD_BITS to a variable instead of a
macro so that the variable holds the value
(1 << threads_per_core) - 1.

> cheers