Re: [PATCH v1 06/11] mm/sparse-vmemmap: refactor vmemmap_populate_basepages()

From
Dan Williams <hidden>
Date
2021-05-05 22:43:41
Reply to
Joao Martins, 2021-03-26
I suspect it's a good sign I'm only finding cosmetic and changelog
changes in the review... I have some more:

A year for now if I'm tracking down a problem and looking through mm
commits I would appreciate a subject line like the following:
"refactor core of vmemmap_populate_basepages() to helper" that gives
an idea of the impact and side effects of the change.

On Thu, Mar 25, 2021 at 4:10 PM Joao Martins [off-list ref] wrote:
I would add a lead in phrase like: "In preparation for describing a
memmap with compound pages, move the actual..."

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.
Aside from the above, looks good.
quoted hunk ↗ jump to hunk
Signed-off-by: Joao Martins <redacted>
---
 mm/sparse-vmemmap.c | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 370728c206ee..8814876edcfa 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -216,33 +216,41 @@ pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
        return pgd;
 }

-int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
-                                        int node, struct vmem_altmap *altmap)
+static int __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 -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);
+       if (!pte)
+               return -ENOMEM;
+       vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
+}
+
+int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
+                                        int node, struct vmem_altmap *altmap)
+{
+       unsigned long addr = start;
+
        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);
-               if (!pte)
+               if (vmemmap_populate_address(addr, node, altmap))
                        return -ENOMEM;
-               vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
        }

        return 0;
--
2.17.1
  






  

    
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