The patch titled
Subject: mm/page_alloc: split prep_compound_page into head and tail subparts
has been added to the -mm tree. Its filename is
mm-page_alloc-split-prep_compound_page-into-head-and-tail-subparts.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-split-prep_compound_page-into-head-and-tail-subparts.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-split-prep_compound_page-into-head-and-tail-subparts.patch
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------------------------------------------------------
From: Joao Martins <joao.m.martins@xxxxxxxxxx>
Subject: mm/page_alloc: split prep_compound_page into head and tail subparts
Split the utility function prep_compound_page() into head and tail
counterparts, and use them accordingly.
This is in preparation for sharing the storage for compound page metadata.
Link: https://lkml.kernel.org/r/20211124191005.20783-3-joao.m.martins@xxxxxxxxxx
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Acked-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-split-prep_compound_page-into-head-and-tail-subparts
+++ a/mm/page_alloc.c
@@ -726,23 +726,33 @@ void free_compound_page(struct page *pag
free_the_page(page, compound_order(page));
}
+static void prep_compound_head(struct page *page, unsigned int order)
+{
+ set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
+ set_compound_order(page, order);
+ atomic_set(compound_mapcount_ptr(page), -1);
+ if (hpage_pincount_available(page))
+ atomic_set(compound_pincount_ptr(page), 0);
+}
+
+static void prep_compound_tail(struct page *head, int tail_idx)
+{
+ struct page *p = head + tail_idx;
+
+ p->mapping = TAIL_MAPPING;
+ set_compound_head(p, head);
+}
+
void prep_compound_page(struct page *page, unsigned int order)
{
int i;
int nr_pages = 1 << order;
__SetPageHead(page);
- for (i = 1; i < nr_pages; i++) {
- struct page *p = page + i;
- p->mapping = TAIL_MAPPING;
- set_compound_head(p, page);
- }
+ for (i = 1; i < nr_pages; i++)
+ prep_compound_tail(page, i);
- set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
- set_compound_order(page, order);
- atomic_set(compound_mapcount_ptr(page), -1);
- if (hpage_pincount_available(page))
- atomic_set(compound_pincount_ptr(page), 0);
+ prep_compound_head(page, order);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
_
Patches currently in -mm which might be from joao.m.martins@xxxxxxxxxx are
memory-failure-fetch-compound_head-after-pgmap_pfn_valid.patch
mm-page_alloc-split-prep_compound_page-into-head-and-tail-subparts.patch
mm-page_alloc-refactor-memmap_init_zone_device-page-init.patch
mm-memremap-add-zone_device-support-for-compound-pages.patch
device-dax-use-align-for-determining-pgoff.patch
device-dax-use-struct_size.patch
device-dax-ensure-dev_dax-pgmap-is-valid-for-dynamic-devices.patch
device-dax-factor-out-page-mapping-initialization.patch
device-dax-set-mapping-prior-to-vmf_insert_pfn_pmdpud.patch
device-dax-compound-devmap-support.patch
