On Tue, 2 Jun 2026 18:10:35 +0800 Muchun Song <[email protected]> wrote:
> Bootmem HugeTLB pages currently defer HVO setup to > hugetlb_vmemmap_init_late(), because the optimization needs zone > information. > > Now that zone initialization is available earlier, the bootmem HVO setup > can be done directly from hugetlb_vmemmap_init_early(). This lets > gigantic HugeTLB pages apply HVO as soon as they are allocated. > > Bootmem gigantic pages that span multiple zones are now filtered out > when they are allocated, so the remaining bootmem gigantic pages seen by > later hugetlb initialization are already zone-valid. As a result, > hugetlb_vmemmap_init_late() no longer needs to handle bootmem HVO setup. > > Signed-off-by: Muchun Song <[email protected]> > --- > mm/hugetlb_vmemmap.c | 67 +++++++++----------------------------------- > 1 file changed, 13 insertions(+), 54 deletions(-) > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index ea6af85bfec1..464578ee246e 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -745,6 +745,8 @@ static bool vmemmap_should_optimize_bootmem_page(struct > huge_bootmem_page *m) > return true; > } > > +static struct zone *pfn_to_zone(unsigned nid, unsigned long pfn); > + > /* > * Initialize memmap section for a gigantic page, HVO-style. > */ > @@ -752,6 +754,7 @@ void __init hugetlb_vmemmap_init_early(int nid) > { > unsigned long psize, paddr, section_size; > unsigned long ns, i, pnum, pfn, nr_pages; > + unsigned long start, end; > struct huge_bootmem_page *m = NULL; > void *map; > > @@ -761,6 +764,8 @@ void __init hugetlb_vmemmap_init_early(int nid) > section_size = (1UL << PA_SECTION_SHIFT); > > list_for_each_entry(m, &huge_boot_pages[nid], list) { > + struct zone *zone; > + > if (!vmemmap_should_optimize_bootmem_page(m)) > continue; > > @@ -769,6 +774,14 @@ void __init hugetlb_vmemmap_init_early(int nid) > paddr = virt_to_phys(m); > pfn = PHYS_PFN(paddr); > map = pfn_to_page(pfn); > + start = (unsigned long)map; > + end = start + hugetlb_vmemmap_size(m->hstate); > + zone = pfn_to_zone(nid, pfn); > + > + if (vmemmap_populate_hvo(start, end, huge_page_order(m->hstate), > + zone, HUGETLB_VMEMMAP_RESERVE_SIZE)) > + panic("Failed to allocate memmap for HugeTLB page\n"); The replaced hugetlb_vmemmap_init_late() path used to fall back to vmemmap_populate() if vmemmap_populate_hvo() returned an error and just lost the HVO optimization for that page. The new path panics on any non-zero return. Is the panic intended, given that vmemmap_populate_hvo() returns -ENOMEM on allocation failure and HVO is normally treated as an optimization rather than a hard requirement? > + > memmap_boot_pages_add(DIV_ROUND_UP(HUGETLB_VMEMMAP_RESERVE_SIZE, PAGE_SIZE)); > > pnum = pfn_to_section_nr(pfn); > ns = psize / section_size; > @@ -800,60 +813,6 @@ static struct zone *pfn_to_zone(unsigned nid, unsigned > long pfn) > > void __init hugetlb_vmemmap_init_late(int nid) > { > - struct huge_bootmem_page *m, *tm; > - unsigned long phys, nr_pages, start, end; > - unsigned long pfn, nr_mmap; > - struct zone *zone = NULL; > - struct hstate *h; > - void *map; > - > - if (!READ_ONCE(vmemmap_optimize_enabled)) > - return; > - > - list_for_each_entry_safe(m, tm, &huge_boot_pages[nid], list) { > - if (!(m->flags & HUGE_BOOTMEM_HVO)) > - continue; > - > - phys = virt_to_phys(m); > - h = m->hstate; > - pfn = PHYS_PFN(phys); > - nr_pages = pages_per_huge_page(h); > - map = pfn_to_page(pfn); > - start = (unsigned long)map; > - end = start + nr_pages * sizeof(struct page); > - > - if (!hugetlb_bootmem_page_zones_valid(nid, m)) { > - /* > - * Oops, the hugetlb page spans multiple zones. > - * Remove it from the list, and populate it normally. > - */ > - list_del(&m->list); > - > - vmemmap_populate(start, end, nid, NULL); > - nr_mmap = end - start; > - memmap_boot_pages_add(DIV_ROUND_UP(nr_mmap, PAGE_SIZE)); > - > - memblock_phys_free(phys, huge_page_size(h)); > - continue; > - } > - > - if (!zone || !zone_spans_pfn(zone, pfn)) > - zone = pfn_to_zone(nid, pfn); > - if (WARN_ON_ONCE(!zone)) > - continue; > - > - if (vmemmap_populate_hvo(start, end, huge_page_order(h), zone, > - HUGETLB_VMEMMAP_RESERVE_SIZE) < 0) { > - /* Fallback if HVO population fails */ > - vmemmap_populate(start, end, nid, NULL); > - nr_mmap = end - start; > - } else { > - m->flags |= HUGE_BOOTMEM_ZONES_VALID; > - nr_mmap = HUGETLB_VMEMMAP_RESERVE_SIZE; > - } > - > - memmap_boot_pages_add(DIV_ROUND_UP(nr_mmap, PAGE_SIZE)); > - } > } > #endif > > -- > 2.54.0 > >
