linux-kernel - Re: [PATCH] drivers: base: update cpu offline info when do hotplug

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Message-ID: <20141020064826.GA4064@kroah.com>
Date:	Mon, 20 Oct 2014 14:48:26 +0800
From:	Greg KH <gregkh@...uxfoundation.org>
To:	Neil Zhang <zhangwm@...vell.com>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drivers: base: update cpu offline info when do hotplug

On Sun, Oct 19, 2014 at 11:39:23PM -0700, Neil Zhang wrote:
>> How much noise is this going to cause on a big/little system that
>> constantly hot unplug/plugs processors all of the time?
> 
> Can you explain more what kind of noise will be introduced on a big/little system?

Have you tested this on such a machine?

> As I know IKS on arm will use cpu_suspend way to power down a core.

Are you sure that it also doesn't use that same functionality to drop a
processor to save power?

Why do you need/want this notification?  What are you going to do with
this information that you don't already have?

thanks,

greg k-h
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