The patch titled
Subject: mm/sparse-vmemmap: refactor core of vmemmap_populate_basepages() to helper
has been added to the -mm tree. Its filename is
mm-sparse-vmemmap-refactor-core-of-vmemmap_populate_basepages-to-helper.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-sparse-vmemmap-refactor-core-of-vmemmap_populate_basepages-to-helper.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-sparse-vmemmap-refactor-core-of-vmemmap_populate_basepages-to-helper.patch
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------------------------------------------------------
From: Joao Martins <joao.m.martins@xxxxxxxxxx>
Subject: mm/sparse-vmemmap: refactor core of vmemmap_populate_basepages() to helper
In preparation for describing a memmap with compound pages, move the
actual pte population logic into a separate function
vmemmap_populate_address() and have vmemmap_populate_basepages() walk
through all base pages it needs to populate.
While doing that, change the helper to use a pte_t* as return value,
rather than an hardcoded errno of 0 or -ENOMEM.
Link: https://lkml.kernel.org/r/20220223194807.12070-3-joao.m.martins@xxxxxxxxxx
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/sparse-vmemmap.c | 46 ++++++++++++++++++++++++++----------------
1 file changed, 29 insertions(+), 17 deletions(-)
--- a/mm/sparse-vmemmap.c~mm-sparse-vmemmap-refactor-core-of-vmemmap_populate_basepages-to-helper
+++ a/mm/sparse-vmemmap.c
@@ -570,33 +570,45 @@ pgd_t * __meminit vmemmap_pgd_populate(u
return pgd;
}
-int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
- int node, struct vmem_altmap *altmap)
+static pte_t * __meminit vmemmap_populate_address(unsigned long addr, int node,
+ struct vmem_altmap *altmap)
{
- unsigned long addr = start;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
+ pgd = vmemmap_pgd_populate(addr, node);
+ if (!pgd)
+ return NULL;
+ p4d = vmemmap_p4d_populate(pgd, addr, node);
+ if (!p4d)
+ return NULL;
+ pud = vmemmap_pud_populate(p4d, addr, node);
+ if (!pud)
+ return NULL;
+ pmd = vmemmap_pmd_populate(pud, addr, node);
+ if (!pmd)
+ return NULL;
+ pte = vmemmap_pte_populate(pmd, addr, node, altmap);
+ if (!pte)
+ return NULL;
+ vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
+
+ return pte;
+}
+
+int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
+ int node, struct vmem_altmap *altmap)
+{
+ unsigned long addr = start;
+ pte_t *pte;
+
for (; addr < end; addr += PAGE_SIZE) {
- pgd = vmemmap_pgd_populate(addr, node);
- if (!pgd)
- return -ENOMEM;
- p4d = vmemmap_p4d_populate(pgd, addr, node);
- if (!p4d)
- return -ENOMEM;
- pud = vmemmap_pud_populate(p4d, addr, node);
- if (!pud)
- return -ENOMEM;
- pmd = vmemmap_pmd_populate(pud, addr, node);
- if (!pmd)
- return -ENOMEM;
- pte = vmemmap_pte_populate(pmd, addr, node, altmap);
+ pte = vmemmap_populate_address(addr, node, altmap);
if (!pte)
return -ENOMEM;
- vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
}
return 0;
_
Patches currently in -mm which might be from joao.m.martins@xxxxxxxxxx are
mm-sparse-vmemmap-add-a-pgmap-argument-to-section-activation.patch
mm-sparse-vmemmap-refactor-core-of-vmemmap_populate_basepages-to-helper.patch
mm-hugetlb_vmemmap-move-comment-block-to-documentation-vm.patch
mm-sparse-vmemmap-improve-memory-savings-for-compound-devmaps.patch
mm-page_alloc-reuse-tail-struct-pages-for-compound-devmaps.patch
