On Thu, Sep 28, 2023 at 04:33:01PM +0800, Yajun Deng wrote: > Subject: mm: pass page count and reserved to __init_single_page We add pass flags that tell __init_single_page() how to initialize page count and PG_Reserved, I think a better subject would be: mm: allow optional initialization of page count and PG_reserved flag > When we init a single page, we need to mark that page reserved when it > is reserved. And some pages need to reset page count, such as compound > pages. > > Introduce enum init_page_flags, the caller will init page count and mark > page reserved by passing INIT_PAGE_COUNT and INIT_PAGE_RESERVED. This does not really describe why the change is needed. How about __init_single_page() unconditionally resets page count which is unnecessary for reserved pages. To allow skipping page count initialization and marking a page reserved in one go add flags parameter to __init_single_page(). No functional changes. > Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx> > --- > v4: move the changes of __init_zone_device_page(). > v3: Introduce enum init_page_flags. > v2: Introduce INIT_PAGE_COUNT and INIT_PAGE_RESERVED. > v1: https://lore.kernel.org/all/20230922070923.355656-1-yajun.deng@xxxxxxxxx/ > --- > mm/hugetlb.c | 2 +- > mm/internal.h | 8 +++++++- > mm/mm_init.c | 24 +++++++++++++----------- > 3 files changed, 21 insertions(+), 13 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index a82dc37669b0..bb9c334a8392 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -3196,7 +3196,7 @@ static void __init hugetlb_folio_init_tail_vmemmap(struct folio *folio, > for (pfn = head_pfn + start_page_number; pfn < end_pfn; pfn++) { > struct page *page = pfn_to_page(pfn); > > - __init_single_page(page, pfn, zone, nid); > + __init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT); > prep_compound_tail((struct page *)folio, pfn - head_pfn); > ret = page_ref_freeze(page, 1); > VM_BUG_ON(!ret); > diff --git a/mm/internal.h b/mm/internal.h > index d7916f1e9e98..449891ad7fdb 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -1209,8 +1209,14 @@ struct vma_prepare { > struct vm_area_struct *remove2; > }; > > +enum init_page_flags { enum page_init_flags please > + INIT_PAGE_COUNT = (1 << 0), > + INIT_PAGE_RESERVED = (1 << 1), > +}; > + > void __meminit __init_single_page(struct page *page, unsigned long pfn, > - unsigned long zone, int nid); > + unsigned long zone, int nid, > + enum init_page_flags flags); > > /* shrinker related functions */ > unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 06a72c223bce..9716c8a7ade9 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -557,11 +557,11 @@ static void __init find_zone_movable_pfns_for_nodes(void) > } > > void __meminit __init_single_page(struct page *page, unsigned long pfn, > - unsigned long zone, int nid) > + unsigned long zone, int nid, > + enum init_page_flags flags) > { > mm_zero_struct_page(page); > set_page_links(page, zone, nid, pfn); > - init_page_count(page); > page_mapcount_reset(page); > page_cpupid_reset_last(page); > page_kasan_tag_reset(page); > @@ -572,6 +572,10 @@ void __meminit __init_single_page(struct page *page, unsigned long pfn, > if (!is_highmem_idx(zone)) > set_page_address(page, __va(pfn << PAGE_SHIFT)); > #endif > + if (flags & INIT_PAGE_COUNT) > + init_page_count(page); > + if (flags & INIT_PAGE_RESERVED) > + __SetPageReserved(page); > } > > #ifdef CONFIG_NUMA > @@ -714,7 +718,7 @@ static void __meminit init_reserved_page(unsigned long pfn, int nid) > if (zone_spans_pfn(zone, pfn)) > break; > } > - __init_single_page(pfn_to_page(pfn), pfn, zid, nid); > + __init_single_page(pfn_to_page(pfn), pfn, zid, nid, INIT_PAGE_COUNT); There is __SetPageReserved call a few lines below, it can be folded here. > } > #else > static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {} > @@ -821,8 +825,8 @@ static void __init init_unavailable_range(unsigned long spfn, > pfn = pageblock_end_pfn(pfn) - 1; > continue; > } > - __init_single_page(pfn_to_page(pfn), pfn, zone, node); > - __SetPageReserved(pfn_to_page(pfn)); > + __init_single_page(pfn_to_page(pfn), pfn, zone, node, > + INIT_PAGE_COUNT | INIT_PAGE_RESERVED); > pgcnt++; > } > > @@ -884,7 +888,7 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone > } > > page = pfn_to_page(pfn); > - __init_single_page(page, pfn, zone, nid); > + __init_single_page(page, pfn, zone, nid, INIT_PAGE_COUNT); > if (context == MEMINIT_HOTPLUG) > __SetPageReserved(page); > > @@ -967,9 +971,6 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn, > unsigned long zone_idx, int nid, > struct dev_pagemap *pgmap) > { > - > - __init_single_page(page, pfn, zone_idx, nid); > - > /* > * Mark page reserved as it will need to wait for onlining > * phase for it to be fully associated with a zone. > @@ -977,7 +978,8 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn, > * We can use the non-atomic __set_bit operation for setting > * the flag as we are still initializing the pages. > */ > - __SetPageReserved(page); > + __init_single_page(page, pfn, zone_idx, nid, > + INIT_PAGE_COUNT | INIT_PAGE_RESERVED); > > /* > * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer > @@ -2058,7 +2060,7 @@ static unsigned long __init deferred_init_pages(struct zone *zone, > } else { > page++; > } > - __init_single_page(page, pfn, zid, nid); > + __init_single_page(page, pfn, zid, nid, INIT_PAGE_COUNT); > nr_pages++; > } > return (nr_pages); > -- > 2.25.1 > -- Sincerely yours, Mike.
