> On Dec 3, 2024, at 10:32, Anshuman Khandual <anshuman.khandual@xxxxxxx> wrote: > > The HugeTLB order check against __NR_USED_SUBPAGE is required only when > HUGETLB_PAGE_OPTIMIZE_VMEMMAP is enabled. Hence BUG_ON() trigger should > happen only when applicable. > > Cc: Muchun Song <muchun.song@xxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Oscar Salvador <osalvador@xxxxxxx> > Cc: linux-mm@xxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > --- > This patch applies on v6.13-rc1 > > Changes in V2: > > - Fixed #ifdef with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP per Oscar > > Changes in V1: > > https://lore.kernel.org/all/20241202090728.78935-1-anshuman.khandual@xxxxxxx/ > > mm/hugetlb.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index ea2ed8e301ef..e6a5b21e3578 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -4513,11 +4513,13 @@ void __init hugetlb_add_hstate(unsigned int order) > struct hstate *h; > unsigned long i; > > - if (size_to_hstate(PAGE_SIZE << order)) { > + if (size_to_hstate(PAGE_SIZE << order)) > return; > - } > + > BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); > +#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > BUG_ON(order < order_base_2(__NR_USED_SUBPAGE)); Hi Anshuman, __NR_USED_SUBPAGE indicates how many struct pages are used to store extra metadata for a HugeTLB page. So we need to make sure the order of a HugeTLB page should be bigger than or equal to order_base_2(__NR_USED_SUBPAGE). So It is not related to HVO. I don't think the changes make sense. Thanks. > +#endif > h = &hstates[hugetlb_max_hstate++]; > __mutex_init(&h->resize_lock, "resize mutex", &h->resize_key); > h->order = order; > -- > 2.30.2 >
