From mboxrd@z Thu Jan  1 00:00:00 1970
From: greg@kroah.com (Greg KH)
Date: Wed, 7 Sep 2016 13:13:36 +0200
Subject: Power saving in case of CPU hotplugin
In-Reply-To: <CAGrgb4USuXpFaRO0aLZuQ4o0MFjWBesktCSctn6PPWS9+cWM+A@mail.gmail.com>
References: <CAGrgb4USuXpFaRO0aLZuQ4o0MFjWBesktCSctn6PPWS9+cWM+A@mail.gmail.com>
Message-ID: <20160907111336.GA10600@kroah.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On Wed, Sep 07, 2016 at 02:31:46PM +0530, Debdipta Ghosh wrote:
> HEllo all,
> 
> I was going through a linux well known concept, hot plugin of cpu cores:
> https://www.kernel.org/doc/Documentation/cpu-hotplug.txt
> 
> Is it more power saving than highest C-State and P-State?
> 
> If we make one cpu offline, it disappears from the OS as it is not present, Is
> that means that CPU is powered off?

It all depends on your hardware.  Some platforms can turn the CPUs off,
some can not.

Sorry, not much help, I know, but the variety of hardware out there in
the world is amazing...

greg k-h