| Message ID | 20250302145555.3236789-4-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix lazy mmu mode | expand |
On 02.03.25 15:55, Ryan Roberts wrote: > With commit 1a10a44dfc1d ("sparc64: implement the new page table range > API") set_ptes was added to the sparc architecture. The implementation > included calling arch_enter/leave_lazy_mmu() calls. > > The patch removes the usage of arch_enter/leave_lazy_mmu() since this > implies nesting of lazy mmu regions which is not supported. Without this > fix, lazy mmu mode is effectively disabled because we exit the mode > after the first set_ptes: > > remap_pte_range() > -> arch_enter_lazy_mmu() > -> set_ptes() > -> arch_enter_lazy_mmu() > -> arch_leave_lazy_mmu() > -> arch_leave_lazy_mmu() > > Powerpc suffered the same problem and fixed it in a corresponding way > with commit 47b8def9358c ("powerpc/mm: Avoid calling > arch_enter/leave_lazy_mmu() in set_ptes"). > > Fixes: 1a10a44dfc1d ("sparc64: implement the new page table range API") > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > arch/sparc/include/asm/pgtable_64.h | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h > index 2b7f358762c1..dc28f2c4eee3 100644 > --- a/arch/sparc/include/asm/pgtable_64.h > +++ b/arch/sparc/include/asm/pgtable_64.h > @@ -936,7 +936,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, > static inline void set_ptes(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, pte_t pte, unsigned int nr) > { > - arch_enter_lazy_mmu_mode(); > for (;;) { > __set_pte_at(mm, addr, ptep, pte, 0); > if (--nr == 0) > @@ -945,7 +944,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, > pte_val(pte) += PAGE_SIZE; > addr += PAGE_SIZE; > } > - arch_leave_lazy_mmu_mode(); > } > #define set_ptes set_ptes > Acked-by: David Hildenbrand <david@redhat.com>
On 2025-03-02 15:55, Ryan Roberts wrote: > With commit 1a10a44dfc1d ("sparc64: implement the new page table range > API") set_ptes was added to the sparc architecture. The implementation > included calling arch_enter/leave_lazy_mmu() calls. > > The patch removes the usage of arch_enter/leave_lazy_mmu() since this > implies nesting of lazy mmu regions which is not supported. Without this > fix, lazy mmu mode is effectively disabled because we exit the mode > after the first set_ptes: > > remap_pte_range() > -> arch_enter_lazy_mmu() > -> set_ptes() > -> arch_enter_lazy_mmu() > -> arch_leave_lazy_mmu() > -> arch_leave_lazy_mmu() > > Powerpc suffered the same problem and fixed it in a corresponding way > with commit 47b8def9358c ("powerpc/mm: Avoid calling > arch_enter/leave_lazy_mmu() in set_ptes"). > > Fixes: 1a10a44dfc1d ("sparc64: implement the new page table range API") > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > arch/sparc/include/asm/pgtable_64.h | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h > index 2b7f358762c1..dc28f2c4eee3 100644 > --- a/arch/sparc/include/asm/pgtable_64.h > +++ b/arch/sparc/include/asm/pgtable_64.h > @@ -936,7 +936,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, > static inline void set_ptes(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, pte_t pte, unsigned int nr) > { > - arch_enter_lazy_mmu_mode(); > for (;;) { > __set_pte_at(mm, addr, ptep, pte, 0); > if (--nr == 0) > @@ -945,7 +944,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, > pte_val(pte) += PAGE_SIZE; > addr += PAGE_SIZE; > } > - arch_leave_lazy_mmu_mode(); > } > #define set_ptes set_ptes Acked-by: Andreas Larsson <andreas@gaisler.com> Thanks, Andreas
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 2b7f358762c1..dc28f2c4eee3 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -936,7 +936,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, static inline void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte, unsigned int nr) { - arch_enter_lazy_mmu_mode(); for (;;) { __set_pte_at(mm, addr, ptep, pte, 0); if (--nr == 0) @@ -945,7 +944,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, pte_val(pte) += PAGE_SIZE; addr += PAGE_SIZE; } - arch_leave_lazy_mmu_mode(); } #define set_ptes set_ptes
With commit 1a10a44dfc1d ("sparc64: implement the new page table range API") set_ptes was added to the sparc architecture. The implementation included calling arch_enter/leave_lazy_mmu() calls. The patch removes the usage of arch_enter/leave_lazy_mmu() since this implies nesting of lazy mmu regions which is not supported. Without this fix, lazy mmu mode is effectively disabled because we exit the mode after the first set_ptes: remap_pte_range() -> arch_enter_lazy_mmu() -> set_ptes() -> arch_enter_lazy_mmu() -> arch_leave_lazy_mmu() -> arch_leave_lazy_mmu() Powerpc suffered the same problem and fixed it in a corresponding way with commit 47b8def9358c ("powerpc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes"). Fixes: 1a10a44dfc1d ("sparc64: implement the new page table range API") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- arch/sparc/include/asm/pgtable_64.h | 2 -- 1 file changed, 2 deletions(-)