Re: [PATCH 05/17] arch, mm: pull out allocation of NODE_DATA to generic code

David Hildenbrand
2024-07-19T15:07:42Z

>>> - * Allocate node data. Try node-local memory and then any node.
>>> - * Never allocate in DMA zone.
>>> - */
>>> - nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
>>> - if (!nd_pa) {
>>> - pr_err("Cannot find %zu bytes in any node (initial node: %d)\n",
>>> - nd_size, nid);
>>> - return;
>>> - }
>>> - nd = __va(nd_pa);
>>> -
>>> - /* report and initialize */
>>> - printk(KERN_INFO "NODE_DATA(%d) allocated [mem %#010Lx-%#010Lx]\n", nid,
>>> - nd_pa, nd_pa + nd_size - 1);
>>> - tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
>>> - if (tnid != nid)
>>> - printk(KERN_INFO " NODE_DATA(%d) on node %d\n", nid, tnid);
>>> -
>>> - node_data[nid] = nd;
>>> - memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
>>> -
>>> - node_set_online(nid);
>>> -}
>>> -
>>> /**
>>> * numa_cleanup_meminfo - Cleanup a numa_meminfo
>>> * @mi: numa_meminfo to clean up
>>> @@ -571,6 +538,7 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
>>> continue;
>>> alloc_node_data(nid);
>>> + node_set_online(nid);
>>> }
>>
>> I can spot that we only remove a single node_set_online() call from x86.
>>
>> What about all the other architectures? Will there be any change in behavior
>> for them? Or do we simply set the nodes online later once more?
>
> On x86 node_set_online() was a part of alloc_node_data() and I moved it
> outside so it's called right after alloc_node_data(). On other
> architectures the allocation didn't include that call, so there should be
> no difference there.

But won't their arch code try setting the nodes online at a later stage?

And I think, some architectures only set nodes online conditionally
(see most other node_set_online() calls).

Sorry if I'm confused here, but with now unconditional node_set_online(), won't
we change the behavior of other architectures?

--
Cheers,

David / dhildenb