Messages in this thread | | | Date | Tue, 23 Oct 2012 19:42:03 +0200 | From | Bart Van Assche <> | Subject | Re: [patch/rfc/rft] sd: allocate request_queue on device's local numa node |
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On 10/23/12 18:52, Jeff Moyer wrote: > Bart Van Assche <bvanassche@acm.org> writes: >> Please keep in mind that a >> single PCIe bus may have a minimal distance to more than one NUMA >> node. See e.g. the diagram at the top of page 8 in >> http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c03261871/c03261871.pdf >> for a system diagram of a NUMA system where each PCIe bus has a >> minimal distance to two different NUMA nodes. > > That's an interesting configuration. I wonder what the numa_node sysfs > file contains for such systems--do you know? I'm not sure how we could > allow this to be user-controlled at probe time. Did you have a specific > mechanism in mind? Module parameters? Something else?
As far as I can see in drivers/pci/pci-sysfs.c the numa_node sysfs attribute contains a single number, even for a topology like the one described above.
With regard to user control of the numa node: I'm not sure how to solve this in general. But for the ib_srp driver this should be easy to do: SCSI host creation is triggered by sending a login string to a sysfs attribute ("add_target"). It wouldn't take much time to add a parameter to that login string that specifies the NUMA node.
Bart.
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