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

David Hildenbrand
2024-07-17T14:42:55Z

On 16.07.24 13:13, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> Architectures that support NUMA duplicate the code that allocates
> NODE_DATA on the node-local memory with slight variations in reporting
> of the addresses where the memory was allocated.
>
> Use x86 version as the basis for the generic alloc_node_data() function
> and call this function in architecture specific numa initialization.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---

[...]

> diff --git a/arch/mips/loongson64/numa.c b/arch/mips/loongson64/numa.c
> index 9208eaadf690..909f6cec3a26 100644
> --- a/arch/mips/loongson64/numa.c
> +++ b/arch/mips/loongson64/numa.c
> @@ -81,12 +81,8 @@ static void __init init_topology_matrix(void)
>
> static void __init node_mem_init(unsigned int node)
> {
> - struct pglist_data *nd;
> unsigned long node_addrspace_offset;
> unsigned long start_pfn, end_pfn;
> - unsigned long nd_pa;
> - int tnid;
> - const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);

One interesting change is that we now always round up to full pages on
architectures where we previously rounded up to SMP_CACHE_BYTES.

I assume we don't really expect a significant growth in memory
consumption that we care about, especially because most systems with
many nodes also have quite some memory around.

> -/* Allocate NODE_DATA for a node on the local memory */
> -static void __init alloc_node_data(int nid)
> -{
> - const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
> - u64 nd_pa;
> - void *nd;
> - int tnid;
> -
> - /*
> - * 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?

--
Cheers,

David / dhildenb