Messages in this thread | | | Date | Wed, 21 Jun 2017 12:27:02 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCHv2 1/3] x86/mm: Provide pmdp_establish() helper |
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On Wed, Jun 21, 2017 at 12:53:03PM +0300, Kirill A. Shutemov wrote: > > > > > > On Thu, Jun 15, 2017 at 05:52:22PM +0300, Kirill A. Shutemov wrote: > > > > > > > We need an atomic way to setup pmd page table entry, avoiding races with > > > > > > > CPU setting dirty/accessed bits. This is required to implement > > > > > > > pmdp_invalidate() that doesn't loose these bits. [...] > Any chance you could help me with arm too?
On arm (ARMv7 with LPAE) we don't have hardware updates of the access/dirty bits, so a generic implementation would suffice. I didn't find one in your patches, so here's an untested version:
static inline pmd_t pmdp_establish(struct mm_struct *mm, unsigned long address, pmd_t *pmdp, pmd_t pmd) { pmd_t old_pmd = *pmdp; set_pmd_at(mm, address, pmdp, pmd); return old_pmd; }
-- Catalin
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