linux-kernel - Re: [PATCH v2] Fix fake numa on ppc

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] [day] [month] [year] [list]

Message-ID: <alpine.DEB.1.00.0909021304210.13939@chino.kir.corp.google.com>
Date:	Wed, 2 Sep 2009 13:09:01 -0700 (PDT)
From:	David Rientjes <rientjes@...gle.com>
To:	Balbir Singh <balbir@...ux.vnet.ibm.com>
cc:	Ankita Garg <ankita@...ibm.com>,
	LKML <linux-kernel@...r.kernel.org>, linuxppc-dev@...abs.org,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>
Subject: Re: [PATCH v2] Fix fake numa on ppc

On Thu, 3 Sep 2009, Balbir Singh wrote:

> > Right, I'm proposing an alternate mapping scheme (which we've used for
> > years) for both platforms such that a cpu is bound (and is set in
> > cpumask_of_node()) to each fake node with which it has physical affinity.
> > That is the only way for zonelist ordering in node order, task migration
> > from offlined cpus, correct sched domains, etc.  I can propose a patchset
> > for x86_64 to do exactly this if there aren't any objections and I hope
> > you'll help do ppc.
> 
> Sounds interesting, I'd definitely be interested in seeing your
> proposal, but I would think of that as additional development on top
> of this patch
> 

Absolutely.  I'm not familiar with numa=fake on ppc, but if cpus are being 
bound to nodes with which they don't have affinity, it definitely warrants 
a fix such as this (although the initial value for fake_enabled looks 
wrong and fake_numa_node_mapping[] can be __cpuinitdata).  I'll cc you, 
Ben, and Ankita on the x86_64 patches.  Thanks.