On Thu, Jun 16, 2022 at 11:38:46AM +0800, Muchun Song wrote:
> The following commit:
>
> commit 641844f5616d ("mm/hugetlb: introduce minimum hugepage order")
>
> fixed a static checker warning and introduced a global variable minimum_order
> to fix the warning. However, the local variable in dissolve_free_huge_pages()
> can be initialized to huge_page_order(&default_hstate) to fix the warning.
> So remove minimum_order to simplify the code.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
> ---
> mm/hugetlb.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 8ea4e51d8186..405d1c7441c9 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -66,12 +66,6 @@ static bool hugetlb_cma_page(struct page *page, unsigned int order)
> #endif
> static unsigned long hugetlb_cma_size __initdata;
>
> -/*
> - * Minimum page order among possible hugepage sizes, set to a proper value
> - * at boot time.
> - */
> -static unsigned int minimum_order __read_mostly = UINT_MAX;
> -
> __initdata LIST_HEAD(huge_boot_pages);
>
> /* for command line parsing */
> @@ -2161,11 +2155,17 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
> unsigned long pfn;
> struct page *page;
> int rc = 0;
> + unsigned int order;
> + struct hstate *h;
>
> if (!hugepages_supported())
> return rc;
>
> - for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) {
> + order = huge_page_order(&default_hstate);
> + for_each_hstate(h)
> + order = min(order, huge_page_order(h));
> +
> + for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) {
> page = pfn_to_page(pfn);
> rc = dissolve_free_huge_page(page);
> if (rc)
> @@ -3157,9 +3157,6 @@ static void __init hugetlb_init_hstates(void)
> struct hstate *h, *h2;
>
> for_each_hstate(h) {
> - if (minimum_order > huge_page_order(h))
> - minimum_order = huge_page_order(h);
> -
> /* oversize hugepages were init'ed in early boot */
> if (!hstate_is_gigantic(h))
> hugetlb_hstate_alloc_pages(h);
> @@ -3184,7 +3181,6 @@ static void __init hugetlb_init_hstates(void)
> h->demote_order = h2->order;
> }
> }
> - VM_BUG_ON(minimum_order == UINT_MAX);
> }
>
> static void __init report_hugepages(void)
> --
> 2.11.0
>
>
--
Oscar Salvador
SUSE Labs
