Re: [PATCH v7] hugetlbfs: Extend the definition of hugepages parameter to support node allocation

Mike Rapoport
2021-09-28T16:47:36Z

Hi,

On Mon, Sep 27, 2021 at 06:41:49PM +0800, Zhenguo Yao wrote:
> We can specify the number of hugepages to allocate at boot. But the
> hugepages is balanced in all nodes at present. In some scenarios,
> we only need hugepages in one node. For example: DPDK needs hugepages
> which are in the same node as NIC. if DPDK needs four hugepages of 1G
> size in node1 and system has 16 numa nodes. We must reserve 64 hugepages
> in kernel cmdline. But, only four hugepages are used. The others should
> be free after boot. If the system memory is low(for example: 64G), it will
> be an impossible task. So, Extending hugepages parameter to support
> specifying hugepages at a specific node.
> For example add following parameter:
>
> hugepagesz=1G hugepages=0:1,1:3
>
> It will allocate 1 hugepage in node0 and 3 hugepages in node1.
>
> Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
> ---

...

> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 9a75ba078e1b..dd40ce6e7565 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -229,17 +229,22 @@ static int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate)
> m->hstate = hstate;
> return 1;
> }
> +
> +bool __init node_specific_alloc_support(void)

I'd suggest to namespace this to hugetlb, e.g.

hugetlb_node_alloc_supported()

> +{
> + return false;
> +}
> #endif
>
>
> -int __init alloc_bootmem_huge_page(struct hstate *h)
> +int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
> {
>
> #ifdef CONFIG_PPC_BOOK3S_64
> if (firmware_has_feature(FW_FEATURE_LPAR) && !radix_enabled())
> return pseries_alloc_bootmem_huge_page(h);
> #endif
> - return __alloc_bootmem_huge_page(h);
> + return __alloc_bootmem_huge_page(h, nid);
> }
>
> #ifndef CONFIG_PPC_BOOK3S_64

...

> @@ -2868,33 +2869,41 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
> return ERR_PTR(-ENOSPC);
> }
>
> -int alloc_bootmem_huge_page(struct hstate *h)
> +int alloc_bootmem_huge_page(struct hstate *h, int nid)
> __attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
> -int __alloc_bootmem_huge_page(struct hstate *h)
> +int __alloc_bootmem_huge_page(struct hstate *h, int nid)
> {
> struct huge_bootmem_page *m;
> int nr_nodes, node;
>
> + if (nid >= nr_online_nodes)
> + return 0;
> + /* do node specific alloc */
> + if (nid != NUMA_NO_NODE) {
> + m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
> + 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
> + if (m)
> + goto found;
> + else
> + return 0;

Nit: you could make it a bit simpler with

if (!m)
return 0;
goto found;

> + }
> + /* do all node balanced alloc */
> for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
> - void *addr;
> -
> - addr = memblock_alloc_try_nid_raw(
> + m = memblock_alloc_try_nid_raw(
> huge_page_size(h), huge_page_size(h),
> 0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
> - if (addr) {
> - /*
> - * Use the beginning of the huge page to store the
> - * huge_bootmem_page struct (until gather_bootmem
> - * puts them into the mem_map).
> - */
> - m = addr;
> + /*
> + * Use the beginning of the huge page to store the
> + * huge_bootmem_page struct (until gather_bootmem
> + * puts them into the mem_map).
> + */
> + if (m)
> goto found;
> - }
> + else
> + return 0;

ditto

> }
> - return 0;
>
> found:
> - BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
> /* Put them into a private list first because mem_map is not up yet */
> INIT_LIST_HEAD(&m->list);
> list_add(&m->list, &huge_boot_pages);

--
Sincerely yours,
Mike.