diff options
Diffstat (limited to 'include/linux/ksm.h')
| -rw-r--r-- | include/linux/ksm.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 899a314bc487..c2dd786a30e1 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -26,6 +26,22 @@ int ksm_disable(struct mm_struct *mm); int __ksm_enter(struct mm_struct *mm); void __ksm_exit(struct mm_struct *mm); +/* + * To identify zeropages that were mapped by KSM, we reuse the dirty bit + * in the PTE. If the PTE is dirty, the zeropage was mapped by KSM when + * deduplicating memory. + */ +#define is_ksm_zero_pte(pte) (is_zero_pfn(pte_pfn(pte)) && pte_dirty(pte)) + +extern unsigned long ksm_zero_pages; + +static inline void ksm_might_unmap_zero_page(struct mm_struct *mm, pte_t pte) +{ + if (is_ksm_zero_pte(pte)) { + ksm_zero_pages--; + mm->ksm_zero_pages--; + } +} static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) { @@ -95,6 +111,10 @@ static inline void ksm_exit(struct mm_struct *mm) { } +static inline void ksm_might_unmap_zero_page(struct mm_struct *mm, pte_t pte) +{ +} + #ifdef CONFIG_MEMORY_FAILURE static inline void collect_procs_ksm(struct page *page, struct list_head *to_kill, int force_early) |