From mboxrd@z Thu Jan 1 00:00:00 1970 From: jbarnes@sgi.com (Jesse Barnes) Date: Wed, 18 Feb 2004 19:04:30 +0000 Subject: Re: PXM/Nid/SLIT patch Message-Id: <20040218190430.GM13235@sgi.com> List-Id: References: <40321CF7.5020301@hp.com> In-Reply-To: <40321CF7.5020301@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Wed, Feb 18, 2004 at 10:59:03AM -0800, David Mosberger wrote: > Christoph> but honestly can't you fix the firmware to return sane > Christoph> information instead? i.e. move the above fix to firmware > Christoph> instead of letting linux fixup the reported data. > > Hmmh, I'm no NUMA-expert and it isn't clear to me whether the patch is > working around a firmware-bug or a limitation in the Linux NUMA code. > I don't see off-hand why it should be illegal to have a memory config > with only one node with memory. The whole PXM_MAGIC business looks > strange to me though. Can someone explain? Well, it would be nice if memory layout was reported fully, with the correct CPU/node and memory affinity information. That would allow us to either interleave in software (maybe a new flag that changes the way discontig.c builds the memory maps) or just treat the machine as a normal NUMA box. But maybe this isn't possible with the HP cell boxes? Robert, maybe you can describe the memory layout of these machines a little more (sorry if I missed some discussion, I'm having mail trouble right now and was unsubscribed from linux-ia64). Thanks, Jesse