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sparc64: remove hugetlb_free_pgd_range()

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Patch series "drop hugetlb_free_pgd_range()".

For all architectures that support hugetlb except for sparc,
hugetlb_free_pgd_range() just calls free_pgd_range().  It turns out the
sparc implementation is essentially identical to free_pgd_range() and can
be removed.  Remove it and update free_pgtables() to treat hugetlb VMAs
the same as others.


This patch (of 3):

The sparc implementation of hugetlb_free_pgd_range() is identical to
free_pgd_range() with the exception of checking for and skipping possible
leaf entries at the PUD and PMD levels.

These checks are unnecessary because any huge pages have been freed and
their PTEs cleared by the time page tables needed to map them are freed. 
While some huge page sizes do populate the page table with multiple PTEs,
they are correctly cleared by huge_ptep_get_and_clear().

To verify this, libhugetlbfs tests were run for 64K, 8M, and 256M page
sizes with an instrumented kernel on a qemu guest modified to support the
256M page size.  The same tests were used to verify no regressions after
applying this patch and were also run on x86 for both 2M and 1G page
sizes.

Link: https://lkml.kernel.org/r/20250716012611.10369-1-anthony.yznaga@oracle.com
Link: https://lkml.kernel.org/r/20250716012611.10369-2-anthony.yznaga@oracle.com
Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Anthony Yznaga
2025-07-15 18:26:09 -07:00
committed by Andrew Morton
parent 6344a6d9ce
commit d0813985a2
2 changed files with 0 additions and 124 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
arch/sparc/include/asm/hugetlb.h
View File

@@ -50,11 +50,6 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
return changed;
}
#define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
unsigned long end, unsigned long floor,
unsigned long ceiling);
#include <asm-generic/hugetlb.h>
#endif /* _ASM_SPARC64_HUGETLB_H */

119
arch/sparc/mm/hugetlbpage.c
View File

@@ -295,122 +295,3 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
return entry;
}
static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
unsigned long addr)
{
pgtable_t token = pmd_pgtable(*pmd);
pmd_clear(pmd);
pte_free_tlb(tlb, token, addr);
mm_dec_nr_ptes(tlb->mm);
}
static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pmd_t *pmd;
unsigned long next;
unsigned long start;
start = addr;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none(*pmd))
continue;
if (is_hugetlb_pmd(*pmd))
pmd_clear(pmd);
else
hugetlb_free_pte_range(tlb, pmd, addr);
} while (pmd++, addr = next, addr != end);
start &= PUD_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PUD_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pmd = pmd_offset(pud, start);
pud_clear(pud);
pmd_free_tlb(tlb, pmd, start);
mm_dec_nr_pmds(tlb->mm);
}
static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pud_t *pud;
unsigned long next;
unsigned long start;
start = addr;
pud = pud_offset(p4d, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
if (is_hugetlb_pud(*pud))
pud_clear(pud);
else
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
ceiling);
} while (pud++, addr = next, addr != end);
start &= PGDIR_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PGDIR_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pud = pud_offset(p4d, start);
p4d_clear(p4d);
pud_free_tlb(tlb, pud, start);
mm_dec_nr_puds(tlb->mm);
}
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pgd_t *pgd;
p4d_t *p4d;
unsigned long next;
addr &= PMD_MASK;
if (addr < floor) {
addr += PMD_SIZE;
if (!addr)
return;
}
if (ceiling) {
ceiling &= PMD_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
end -= PMD_SIZE;
if (addr > end - 1)
return;
pgd = pgd_offset(tlb->mm, addr);
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
if (p4d_none_or_clear_bad(p4d))
continue;
hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
} while (p4d++, addr = next, addr != end);
}