diff options
Diffstat (limited to 'mm/ksm.c')
| -rw-r--r-- | mm/ksm.c | 104 |
1 files changed, 87 insertions, 17 deletions
@@ -515,6 +515,28 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr) return (ret & VM_FAULT_OOM) ? -ENOMEM : 0; } +static bool vma_ksm_compatible(struct vm_area_struct *vma) +{ + if (vma->vm_flags & (VM_SHARED | VM_MAYSHARE | VM_PFNMAP | + VM_IO | VM_DONTEXPAND | VM_HUGETLB | + VM_MIXEDMAP)) + return false; /* just ignore the advice */ + + if (vma_is_dax(vma)) + return false; + +#ifdef VM_SAO + if (vma->vm_flags & VM_SAO) + return false; +#endif +#ifdef VM_SPARC_ADI + if (vma->vm_flags & VM_SPARC_ADI) + return false; +#endif + + return true; +} + static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm, unsigned long addr) { @@ -1026,6 +1048,7 @@ mm_exiting: mm_slot_free(mm_slot_cache, mm_slot); clear_bit(MMF_VM_MERGEABLE, &mm->flags); + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); mmdrop(mm); } else spin_unlock(&ksm_mmlist_lock); @@ -2408,6 +2431,7 @@ no_vmas: mm_slot_free(mm_slot_cache, mm_slot); clear_bit(MMF_VM_MERGEABLE, &mm->flags); + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); mmap_read_unlock(mm); mmdrop(mm); } else { @@ -2485,6 +2509,66 @@ static int ksm_scan_thread(void *nothing) return 0; } +static void __ksm_add_vma(struct vm_area_struct *vma) +{ + unsigned long vm_flags = vma->vm_flags; + + if (vm_flags & VM_MERGEABLE) + return; + + if (vma_ksm_compatible(vma)) + vm_flags_set(vma, VM_MERGEABLE); +} + +/** + * ksm_add_vma - Mark vma as mergeable if compatible + * + * @vma: Pointer to vma + */ +void ksm_add_vma(struct vm_area_struct *vma) +{ + struct mm_struct *mm = vma->vm_mm; + + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + __ksm_add_vma(vma); +} + +static void ksm_add_vmas(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + + VMA_ITERATOR(vmi, mm, 0); + for_each_vma(vmi, vma) + __ksm_add_vma(vma); +} + +/** + * ksm_enable_merge_any - Add mm to mm ksm list and enable merging on all + * compatible VMA's + * + * @mm: Pointer to mm + * + * Returns 0 on success, otherwise error code + */ +int ksm_enable_merge_any(struct mm_struct *mm) +{ + int err; + + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + return 0; + + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { + err = __ksm_enter(mm); + if (err) + return err; + } + + set_bit(MMF_VM_MERGE_ANY, &mm->flags); + ksm_add_vmas(mm); + + return 0; +} + int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags) { @@ -2493,25 +2577,10 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, switch (advice) { case MADV_MERGEABLE: - /* - * Be somewhat over-protective for now! - */ - if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | - VM_PFNMAP | VM_IO | VM_DONTEXPAND | - VM_HUGETLB | VM_MIXEDMAP)) - return 0; /* just ignore the advice */ - - if (vma_is_dax(vma)) + if (vma->vm_flags & VM_MERGEABLE) return 0; - -#ifdef VM_SAO - if (*vm_flags & VM_SAO) + if (!vma_ksm_compatible(vma)) return 0; -#endif -#ifdef VM_SPARC_ADI - if (*vm_flags & VM_SPARC_ADI) - return 0; -#endif if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { err = __ksm_enter(mm); @@ -2615,6 +2684,7 @@ void __ksm_exit(struct mm_struct *mm) if (easy_to_free) { mm_slot_free(mm_slot_cache, mm_slot); + clear_bit(MMF_VM_MERGE_ANY, &mm->flags); clear_bit(MMF_VM_MERGEABLE, &mm->flags); mmdrop(mm); } else if (mm_slot) { |