From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cliff Wickman Subject: Re: numactl using it's own affinity to determine CPU set Date: Tue, 23 Oct 2012 09:19:18 -0500 Message-ID: <20121023141918.GA27082@sgi.com> References: <20121022194141.GT16230@one.firstfloor.org> <20121023122139.GA5766@machinehead.brq.redhat.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20121023122139.GA5766@machinehead.brq.redhat.com> Sender: linux-numa-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Petr Holasek Cc: Jon Stanley , Andi Kleen , linux-numa@vger.kernel.org Hi Petr, On Tue, Oct 23, 2012 at 02:21:40PM +0200, Petr Holasek wrote: > Hi everyone, > > On Mon, 22 Oct 2012, Jon Stanley wrote: > > On Mon, Oct 22, 2012 at 3:41 PM, Andi Kleen wrote: > > > That was done intentional at some point to handle cpusets. > > > numactl 1.0 or so didn't have that problem. > > > > I'll happily admit to not being an expert here :) > > I've added new interface for parsing cpusets/nodesets with _all() suffix > in 2.0.8-rc5 libnuma, but numactl utility still uses old ones with cpuset > awareness. I didn't want to dig into some libnuma internals and change > behaviour of dependent utils in such way. > > > > > However, I thought that the concept of cpusets was that if you > > attempted to set affinity outside of your cpuset, that would silently > > fail. I assume that the reason that libnuma didn't want to set outside > > of it's own affinity mask is to avoid such a silent failure? > > > > Also, I question the Real World(TM) prevalence of cpusets. > > > > > However it's unclear if it's really bug. > > > > Not sure if I'd call it a bug since it was intentional, but sure would > > call it an unexpected change in behavior :) > > I like the idea of some overriding option proposed by Andi. > > btw, Cliff, can you remember what was the reason for this change in some > version after 1.0? > > Petr Memory nodes allowed was made cpuset-aware by the below patch. I'm not quite sure if this is the change you are asking about. patch 0804_ls_patch2 From: Lee Schermerhorn Date: Wed, 02 Apr 2008 14:34:37 -0400 Depends-on: MPOL_F_MEMS_ALLOWED kernel patch Provide libnuma API for MPOL_F_MEMS_ALLOWED flag. Return nodes allowed by the application's current cpuset context via new API numa_get_mems_allowed(). +.BR numa_get_mems_allowed() +returns the mask of nodes from which the process is allowed to allocate +memory in it's current cpuset context. -Cliff -- Cliff Wickman SGI cpw@sgi.com (651) 683-3824