Messages in this thread | | | Date | Thu, 21 Apr 2022 10:05:36 -0700 (PDT) | Subject | Re: [PATCH v4] riscv: mm: Remove the copy operation of pmd | From | Palmer Dabbelt <> |
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On Thu, 31 Mar 2022 19:43:20 PDT (-0700), hanchuanhua@oppo.com wrote: > Since all processes share the kernel address space, > we only need to copy pgd in case of a vmalloc page > fault exception, the other levels of page tables are > shared, so the operation of copying pmd is unnecessary. > > Signed-off-by: Chuanhua Han <hanchuanhua@oppo.com> > --- > Changes in v4: > -Modify incorrect author name. > > Changes in v3: > -Change the real name of signed-off-by. > > Changes in v2: > -Delete incorrect default signatures. > > > arch/riscv/mm/fault.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c > index 4e9efbe46d5f..40694f0cab9e 100644 > --- a/arch/riscv/mm/fault.c > +++ b/arch/riscv/mm/fault.c > @@ -102,9 +102,9 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code > static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr) > { > pgd_t *pgd, *pgd_k; > - pud_t *pud, *pud_k; > - p4d_t *p4d, *p4d_k; > - pmd_t *pmd, *pmd_k; > + pud_t *pud_k; > + p4d_t *p4d_k; > + pmd_t *pmd_k; > pte_t *pte_k; > int index; > unsigned long pfn; > @@ -132,14 +132,12 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a > } > set_pgd(pgd, *pgd_k); > > - p4d = p4d_offset(pgd, addr); > p4d_k = p4d_offset(pgd_k, addr); > if (!p4d_present(*p4d_k)) { > no_context(regs, addr); > return; > } > > - pud = pud_offset(p4d, addr); > pud_k = pud_offset(p4d_k, addr); > if (!pud_present(*pud_k)) { > no_context(regs, addr); > @@ -150,13 +148,11 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a > * Since the vmalloc area is global, it is unnecessary > * to copy individual PTEs > */ > - pmd = pmd_offset(pud, addr); > pmd_k = pmd_offset(pud_k, addr); > if (!pmd_present(*pmd_k)) { > no_context(regs, addr); > return; > } > - set_pmd(pmd, *pmd_k); > > /* > * Make sure the actual PTE exists as well to
Thanks, this is on for-next (it was last night, but looks like I forgot to send the email).
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