Messages in this thread | | | Date | Wed, 4 Mar 2015 14:45:47 +0900 | From | Kamezawa Hiroyuki <> | Subject | Re: [PATCH] workqueue: update numa affinity when node hotplug |
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On 2015/03/03 22:18, Tejun Heo wrote: > Hello, Kame. > > On Tue, Mar 03, 2015 at 03:53:46PM +0900, Kamezawa Hiroyuki wrote: >> relationship between proximity domain and lapic id doesn't change. >> relationship between lapic-id and cpu-id changes. >> >> pxm <-> memory address : no change >> pxm <-> lapicid : no change >> pxm <-> node id : no change >> lapicid <-> cpu id : change. > > So, we're changing the cpu ID to NUMA node mapping because current > NUMA code is ignoring PXM for memoryless nodes? That's it? >
For memory-less node case, yes. Another problem is that lapicid <-> cpuid relationship is not persistent.
>>>> I personally thinks proper fix is building persistent cpu-id <-> lapicid relationship as >>>> pxm does rather than creating band-aid. >>> >>> Oh if this is possible, I agree that's the right direction too. >>> >> >> Implementation is a bit complicated now :(. > > Ah well, even then, the obviously right thing to do is updating NUMA > code to always keep track of PXM information. We don't really want to > pile NUMA hacks in random users of NUMA code. >
We'd like to start from making apicid <-> cpuid persistent because memory-less node case doesn't cause panic.
Gu-san, how do you think ?
Thanks, -Kame
P.S. Finally, I want something like udev for cpuid/numaid...
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