* John David Anglin <[email protected]>: > On 2026-07-25 12:27 p.m., Helge Deller wrote: > > On 7/24/26 17:48, Usama Arif wrote: > >> > >> > >> On 24/07/2026 16:32, Pedro Falcato wrote: > >>> On Fri, Jul 24, 2026 at 04:03:44PM +0100, Usama Arif wrote: > >>>> > >>>> > >>>> On 24/07/2026 15:14, Matthew Wilcox wrote: > >>>>> On Fri, Jul 24, 2026 at 02:36:59PM +0100, Usama Arif wrote: > >>>>>> > >>>>>> > >>>>>> On 24/07/2026 11:20, Pedro Falcato wrote: > >>>>>>> ptep_get() does not need write access to the PTE. > >>>>>>> > >>>>>>> Signed-off-by: Pedro Falcato <[email protected]> > >>>>>>> --- > >>>>>>> arch/parisc/include/asm/pgtable.h | 2 +- > >>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>>>>>> > >>>>>> hmm I think you might break build bisectibility if > >>>>>> you separate out the patches, you should squash patch 3 and 4, > >>>>>> with patch 1. > >>>>> > >>>>> I don't see how this breaks bisectability. Can you elaborate on what > >>>>> you think would break? > >>>> > >>>> Patch 1 does: > >>>> > >>>> -static inline pte_t ptep_get_lockless(pte_t *ptep) > >>>> +static inline pte_t ptep_get_lockless(const pte_t *ptep) > >>>> { > >>>> return ptep_get(ptep); > >>>> } > >>>> > >>>> > >>>> ptep_get() takes a non-const arg till patch 3 for example for parsic. > >>>> I don't think you can pass a const variable to non const function arg? > >>>> > >>>> So parsic won't compile in patch 1 and 2, powerprc wont compile > >>>> for patches 1, 2 and 3.. > >>> > >>> Aha, yes, nice catch! I'll have to rethink that. Maybe squashing the > >>> patches > >>> would be the cleanest way forward. > >>> > >> > >> Yes, squashing is the simplest way forward. > >> > >>> FWIW, the vast majority of architectures aren't doing funny things on > >>> ptep_get(). E.g PA-RISC, loongarch only define these so they can use it in > >>> their own asm/pgtable.h. I'd really like to delete these but I can't tell > >>> if they are *actually* required. > >>> > >> > >> Ah maybe there is something in git history on why it was needed? > >> > >> If not, hopefully someone from the arch lists could clarify.. > > I tried to remove ptep_get() and ptep_test_and_clear_young() from > > arch/parisc/include/asm/pgtable.h, but this then triggers compile errors: > > > > CC arch/parisc/kernel/asm-offsets.s > > In file included from > > /home/cvs/parisc/git-kernel/linus-linux-2.6/include/linux/mm.h:31, > > from > > /home/cvs/parisc/git-kernel/linus-linux-2.6/include/linux/pid_namespace.h:7, > > from > > /home/cvs/parisc/git-kernel/linus-linux-2.6/include/linux/ptrace.h:10, > > from > > /home/cvs/parisc/git-kernel/linus-linux-2.6/arch/parisc/kernel/asm-offsets.c:21: > > /home/cvs/parisc/git-kernel/linus-linux-2.6/include/linux/pgtable.h: In > > function ‘clear_young_dirty_ptes’: > > /home/cvs/parisc/git-kernel/linus-linux-2.6/include/linux/pgtable.h:683:25: > > error: implicit declaration of function ‘ptep_test_and_clear_young’; > > did you mean ‘pmdp_test_and_clear_young’? [-Wimplicit-function-declaration] > > 683 | ptep_test_and_clear_young(vma, addr, ptep); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > > | pmdp_test_and_clear_young > > > > So, I think the answer is, that the local copy of ptep_get() is used in the > > parisc implementation of > > ptep_test_and_clear_young() function. > > > > Switching to the default include/linux/pgtable.h seems not easy doable.... > > Did you remove define for __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG in parisc > version of pgtable.h?
Indeed, I missed to remove that. Usama, if you want you can add the patch below to your patch set, thus simplifying your series? Helge ------ From: Helge Deller <[email protected]> Date: Sat, 25 Jul 2026 19:19:55 +0200 Subject: [PATCH] parisc: Drop own implementations for ptep_get() and ptep_test_and_clear_young() Switch to the generic implementations, which are identical. Suggested-by: Usama Arif <[email protected]> Suggested-by: John David Anglin <[email protected]> Signed-off-by: Helge Deller <[email protected]> diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h index 467b8547ac8b..d92dee9fef3f 100644 --- a/arch/parisc/include/asm/pgtable.h +++ b/arch/parisc/include/asm/pgtable.h @@ -432,25 +432,6 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) return pte; } -static inline pte_t ptep_get(pte_t *ptep) -{ - return READ_ONCE(*ptep); -} -#define ptep_get ptep_get - -static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) -{ - pte_t pte; - - pte = ptep_get(ptep); - if (!pte_young(pte)) { - return false; - } - set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte)); - return true; -} - bool ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep); pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep); @@ -491,7 +472,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, #define HAVE_ARCH_UNMAPPED_AREA #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN -#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH #define __HAVE_ARCH_PTEP_CLEAR_FLUSH #define __HAVE_ARCH_PTEP_SET_WRPROTECT
