From: Andi Kleen <andi@firstfloor.org>
To: Kornilios Kourtis <kkourt@cslab.ece.ntua.gr>
Cc: Andi Kleen <andi@firstfloor.org>, linux-numa@vger.kernel.org
Subject: Re: find the node that a cpu belongs to
Date: Tue, 17 Mar 2009 12:59:07 +0100 [thread overview]
Message-ID: <20090317115907.GS11935@one.firstfloor.org> (raw)
In-Reply-To: <20090317113242.GA30922@solar.cslab.ece.ntua.gr>
On Tue, Mar 17, 2009 at 01:32:42PM +0200, Kornilios Kourtis wrote:
> On Tue, Mar 17, 2009 at 11:45:22AM +0100, Andi Kleen wrote:
> > On Tue, Mar 17, 2009 at 03:09:10AM +0200, Kornilios Kourtis wrote:
> > > Hi,
> > >
> > > I was wondering if you would be interested in adding a libnuma function
> > > for determing the node that a cpu belongs to.
> >
> > Concrete use case please. Why would you want to do that in a program?
>
> My specific case is quite simple: I have a program that creates a number
> of threads that are bound to run in specific cpus. I want to pre-allocate
> memory in the node of the cpu that the thread will run before the threads
> are created using numa_alloc_onnode().
Normally the number of threads is dependent on the data layout, isn't it?
It seems like a backwards way of doing things, but ok.
BTW another known topology reporting hole is there is currently no way
to report number of CPUs for a given node. Normally it's just max/cpus,
but that can change with CPU hotplug. On the other hand CPU/node hotplug
is currently not really supported anyways.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-03-17 11:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-17 1:09 find the node that a cpu belongs to Kornilios Kourtis
2009-03-17 10:45 ` Andi Kleen
2009-03-17 11:32 ` Kornilios Kourtis
2009-03-17 11:59 ` Andi Kleen [this message]
2009-03-18 15:19 ` Kornilios Kourtis
2009-03-19 14:16 ` Cliff Wickman
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