Hi Kamazawa-san, On 03/04/2015 01:45 PM, Kamezawa Hiroyuki wrote: > 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 ?
Fine by me. But it seems that the change will break the re-use of free cpuid when hot add new cpus, I am afraid it may affect other sub-systems, though I can not point out the specific example. Thanks, Gu > > Thanks, > -Kame > > P.S. > Finally, I want something like udev for cpuid/numaid... > > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/