linux-kernel - Re: [PATCH] Correct nr_processes() when CPUs have been unplugged

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 4 Nov 2009 11:44:20 -0800
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Christoph Lameter <cl@...ux-foundation.org>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Ian Campbell <Ian.Campbell@...rix.com>,
	Tejun Heo <tj@...nel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Correct nr_processes() when CPUs have been unplugged

On Wed, Nov 04, 2009 at 02:37:06PM -0500, Christoph Lameter wrote:
> On Tue, 3 Nov 2009, Paul E. McKenney wrote:
> 
> > > Cpu hotplug is rarely used (what you listed are rare and unusual cases)
> > > and therefore online cpus == possible cpus == present cpus.
> >
> > Though it is not unusual for "possible cpus" to be quite a bit larger
> > than "online cpus"...
> 
> The only reason for possible cpus to be larger than online cpus is if you
> can actually plugin more processors while the system is running. Typically
> the larger possible cpus seems to be some sort of Vendor BIOS screwup
> where the vendor advertises how many processors the maximum configuration
> of a certain type of hardware would suppport if one would buy that config.

Or if you are running as a guest OS on top of some sort of hypervisor.

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