diff options
| author | David Hildenbrand <david@redhat.com> | 2025-09-01 17:03:30 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-21 14:22:03 -0700 |
| commit | 50765b46ab44544f661fb70923871f8d06381015 (patch) | |
| tree | b2fc00afab110d0a5bbb783111a63fe1fe086c11 | |
| parent | 7b4f21f5e0386dfe02c68c009294d8f26e3c1bad (diff) | |
mm/mm_init: make memmap_init_compound() look more like prep_compound_page()
Grepping for "prep_compound_page" leaves on clueless how devdax gets its
compound pages initialized.
Let's add a comment that might help finding this open-coded
prep_compound_page() initialization more easily.
Further, let's be less smart about the ordering of initialization and just
perform the prep_compound_head() call after all tail pages were
initialized: just like prep_compound_page() does.
No need for a comment to describe the initialization order: again, just
like prep_compound_page().
Link: https://lkml.kernel.org/r/20250901150359.867252-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/mm_init.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/mm/mm_init.c b/mm/mm_init.c index 5c21b3af216b..df614556741a 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1091,6 +1091,12 @@ static void __ref memmap_init_compound(struct page *head, unsigned long pfn, end_pfn = head_pfn + nr_pages; unsigned int order = pgmap->vmemmap_shift; + /* + * We have to initialize the pages, including setting up page links. + * prep_compound_page() does not take care of that, so instead we + * open-code prep_compound_page() so we can take care of initializing + * the pages in the same go. + */ __SetPageHead(head); for (pfn = head_pfn + 1; pfn < end_pfn; pfn++) { struct page *page = pfn_to_page(pfn); @@ -1098,15 +1104,8 @@ static void __ref memmap_init_compound(struct page *head, __init_zone_device_page(page, pfn, zone_idx, nid, pgmap); prep_compound_tail(head, pfn - head_pfn); set_page_count(page, 0); - - /* - * The first tail page stores important compound page info. - * Call prep_compound_head() after the first tail page has - * been initialized, to not have the data overwritten. - */ - if (pfn == head_pfn + 1) - prep_compound_head(head, order); } + prep_compound_head(head, order); } void __ref memmap_init_zone_device(struct zone *zone, |