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From: "Parthasarathy, Mohan (In-Memory Compute Platforms)" <mohan_parthasarathy@hpe.com>
To: "linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>
Subject: How to connect a CXL memory device to a NUMA node ?
Date: Fri, 5 Apr 2024 10:36:37 +0000	[thread overview]
Message-ID: <PH7PR84MB158244A35FB3A633E6E0DFE888032@PH7PR84MB1582.NAMPRD84.PROD.OUTLOOK.COM> (raw)

Hi all,

I want to create a VM with 2 CXL memory devices - one attached to NUMA node 0 and one attached to NUMA node 1. Is this possible in QEMU ? Currently when I create a CXL memory device in QEMU, it shows equal distances from each numa node in numactl output. I want it such that it should show closer distance to the NUMA node (or socket) it is attached to. Something like this :

[fedora@localhost ~]$ numactl -H
available: 3 nodes (0-2)
node 0 cpus: 0 1
node 0 size: 1894 MB
node 0 free: 1627 MB
node 1 cpus: 2 3
node 1 size: 2012 MB
node 1 free: 1696 MB
node 2 cpus:
node 2 size: 4096 MB
node 2 free: 4096 MB
node distances:
node   0   1   2
  0:  10  20  20
  1:  20  10  30
  2:  20  20  10

As you can see the distance for numa node 1 to the cxl device should be 30, not 20, assuming the CXL device is attached to node 0. Any thoughts on how to make this work ?

Regards,
Mohan

             reply	other threads:[~2024-04-05 10:39 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-05 10:36 Parthasarathy, Mohan (In-Memory Compute Platforms) [this message]
2024-04-05 13:29 ` How to connect a CXL memory device to a NUMA node ? Jonathan Cameron

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