Message ID | 20241219164425.2277022-6-kevin.brodsky@arm.com |
---|---|
State | New |
Headers | show |
Series | Account page tables at all levels | expand |
Hi Kevin, On 19/12/2024 17:44, Kevin Brodsky wrote: > {pmd,pud,p4d}_alloc_one() is never called if the corresponding page > table level is folded, as {pmd,pud,p4d}_alloc() already does the > required check. We can therefore remove the runtime page table level > checks in {pud,p4d}_alloc_one. The PUD helper becomes equivalent to > the generic version, so we remove it altogether. > > This is consistent with the way arm64 and x86 handle this situation > (runtime check in p4d_free() only). > > Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> > --- > arch/riscv/include/asm/pgalloc.h | 22 ++++------------------ > 1 file changed, 4 insertions(+), 18 deletions(-) > > diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h > index f52264304f77..8ad0bbe838a2 100644 > --- a/arch/riscv/include/asm/pgalloc.h > +++ b/arch/riscv/include/asm/pgalloc.h > @@ -12,7 +12,6 @@ > #include <asm/tlb.h> > > #ifdef CONFIG_MMU > -#define __HAVE_ARCH_PUD_ALLOC_ONE > #define __HAVE_ARCH_PUD_FREE > #include <asm-generic/pgalloc.h> > > @@ -88,15 +87,6 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, > } > } > > -#define pud_alloc_one pud_alloc_one > -static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) > -{ > - if (pgtable_l4_enabled) > - return __pud_alloc_one(mm, addr); > - > - return NULL; > -} > - > #define pud_free pud_free > static inline void pud_free(struct mm_struct *mm, pud_t *pud) > { > @@ -118,15 +108,11 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, > #define p4d_alloc_one p4d_alloc_one > static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr) > { > - if (pgtable_l5_enabled) { > - gfp_t gfp = GFP_PGTABLE_USER; > - > - if (mm == &init_mm) > - gfp = GFP_PGTABLE_KERNEL; > - return (p4d_t *)get_zeroed_page(gfp); > - } > + gfp_t gfp = GFP_PGTABLE_USER; > > - return NULL; > + if (mm == &init_mm) > + gfp = GFP_PGTABLE_KERNEL; > + return (p4d_t *)get_zeroed_page(gfp); > } > > static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d) Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks, Alex
+Qi On 03/01/2025 11:31, Alexandre Ghiti wrote: > Hi Kevin, > > On 19/12/2024 17:44, Kevin Brodsky wrote: >> {pmd,pud,p4d}_alloc_one() is never called if the corresponding page >> table level is folded, as {pmd,pud,p4d}_alloc() already does the >> required check. We can therefore remove the runtime page table level >> checks in {pud,p4d}_alloc_one. The PUD helper becomes equivalent to >> the generic version, so we remove it altogether. >> >> This is consistent with the way arm64 and x86 handle this situation >> (runtime check in p4d_free() only). >> >> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> >> --- >> arch/riscv/include/asm/pgalloc.h | 22 ++++------------------ >> 1 file changed, 4 insertions(+), 18 deletions(-) >> >> diff --git a/arch/riscv/include/asm/pgalloc.h >> b/arch/riscv/include/asm/pgalloc.h >> index f52264304f77..8ad0bbe838a2 100644 >> --- a/arch/riscv/include/asm/pgalloc.h >> +++ b/arch/riscv/include/asm/pgalloc.h >> @@ -12,7 +12,6 @@ >> #include <asm/tlb.h> >> #ifdef CONFIG_MMU >> -#define __HAVE_ARCH_PUD_ALLOC_ONE >> #define __HAVE_ARCH_PUD_FREE >> #include <asm-generic/pgalloc.h> >> @@ -88,15 +87,6 @@ static inline void pgd_populate_safe(struct >> mm_struct *mm, pgd_t *pgd, >> } >> } >> -#define pud_alloc_one pud_alloc_one >> -static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned >> long addr) >> -{ >> - if (pgtable_l4_enabled) >> - return __pud_alloc_one(mm, addr); >> - >> - return NULL; >> -} >> - >> #define pud_free pud_free >> static inline void pud_free(struct mm_struct *mm, pud_t *pud) >> { >> @@ -118,15 +108,11 @@ static inline void __pud_free_tlb(struct >> mmu_gather *tlb, pud_t *pud, >> #define p4d_alloc_one p4d_alloc_one >> static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned >> long addr) >> { >> - if (pgtable_l5_enabled) { >> - gfp_t gfp = GFP_PGTABLE_USER; >> - >> - if (mm == &init_mm) >> - gfp = GFP_PGTABLE_KERNEL; >> - return (p4d_t *)get_zeroed_page(gfp); >> - } >> + gfp_t gfp = GFP_PGTABLE_USER; >> - return NULL; >> + if (mm == &init_mm) >> + gfp = GFP_PGTABLE_KERNEL; >> + return (p4d_t *)get_zeroed_page(gfp); >> } >> static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d) > > > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks for the review! Just FYI this patch is now part of Qi's series [1], I will drop it when posting the next version of this series. - Kevin [1] https://lore.kernel.org/linux-mm/84ddf857508b98a195a790bc6ff6ab8849b44633.1735549103.git.zhengqi.arch@bytedance.com/
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h index f52264304f77..8ad0bbe838a2 100644 --- a/arch/riscv/include/asm/pgalloc.h +++ b/arch/riscv/include/asm/pgalloc.h @@ -12,7 +12,6 @@ #include <asm/tlb.h> #ifdef CONFIG_MMU -#define __HAVE_ARCH_PUD_ALLOC_ONE #define __HAVE_ARCH_PUD_FREE #include <asm-generic/pgalloc.h> @@ -88,15 +87,6 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, } } -#define pud_alloc_one pud_alloc_one -static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) -{ - if (pgtable_l4_enabled) - return __pud_alloc_one(mm, addr); - - return NULL; -} - #define pud_free pud_free static inline void pud_free(struct mm_struct *mm, pud_t *pud) { @@ -118,15 +108,11 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, #define p4d_alloc_one p4d_alloc_one static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr) { - if (pgtable_l5_enabled) { - gfp_t gfp = GFP_PGTABLE_USER; - - if (mm == &init_mm) - gfp = GFP_PGTABLE_KERNEL; - return (p4d_t *)get_zeroed_page(gfp); - } + gfp_t gfp = GFP_PGTABLE_USER; - return NULL; + if (mm == &init_mm) + gfp = GFP_PGTABLE_KERNEL; + return (p4d_t *)get_zeroed_page(gfp); } static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
{pmd,pud,p4d}_alloc_one() is never called if the corresponding page table level is folded, as {pmd,pud,p4d}_alloc() already does the required check. We can therefore remove the runtime page table level checks in {pud,p4d}_alloc_one. The PUD helper becomes equivalent to the generic version, so we remove it altogether. This is consistent with the way arm64 and x86 handle this situation (runtime check in p4d_free() only). Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> --- arch/riscv/include/asm/pgalloc.h | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-)