Messages in this thread | | | Date | Fri, 29 Sep 2023 17:37:13 +0800 | Subject | Re: [PATCH v4 1/2] mm: pass page count and reserved to __init_single_page | From | Yajun Deng <> |
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On 2023/9/29 16:19, Mike Rapoport wrote: > 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 Okay. >> 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. Okay. >> Signed-off-by: Yajun Deng <yajun.deng@linux.dev> >> --- >> 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@linux.dev/ >> --- >> 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 Okay. >> + 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. > No, There is a #ifdef in front of it. If so, I need to add __SetPageReserved to another init_reserved_page().
And there is an return before __init_single_page. I will change INIT_PAGE_COUNT to 0 in next patch.
>> } >> #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 >>
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