The patch titled thp: khugepaged: make khugepaged aware about madvise has been removed from the -mm tree. Its filename was thp-khugepaged-make-khugepaged-aware-of-madvise.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: thp: khugepaged: make khugepaged aware about madvise From: Andrea Arcangeli <aarcange@xxxxxxxxxx> MADV_HUGEPAGE and MADV_NOHUGEPAGE were fully effective only if run after mmap and before touching the memory. While this is enough for most usages, it's little effort to make madvise more dynamic at runtime on an existing mapping by making khugepaged aware about madvise. MADV_HUGEPAGE: register in khugepaged immediately without waiting a page fault (that may not ever happen if all pages are already mapped and the "enabled" knob was set to madvise during the initial page faults). MADV_NOHUGEPAGE: skip vmas marked VM_NOHUGEPAGE in khugepaged to stop collapsing pages where not needed. [akpm@xxxxxxxxxxxxxxxxxxxx: tweak comment] Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/huge_mm.h | 6 ++++-- mm/huge_memory.c | 23 +++++++++++++++++++---- mm/madvise.c | 2 +- 3 files changed, 24 insertions(+), 7 deletions(-) diff -puN include/linux/huge_mm.h~thp-khugepaged-make-khugepaged-aware-of-madvise include/linux/huge_mm.h --- a/include/linux/huge_mm.h~thp-khugepaged-make-khugepaged-aware-of-madvise +++ a/include/linux/huge_mm.h @@ -105,7 +105,8 @@ extern void __split_huge_page_pmd(struct #if HPAGE_PMD_ORDER > MAX_ORDER #error "hugepages can't be allocated by the buddy allocator" #endif -extern int hugepage_madvise(unsigned long *vm_flags, int advice); +extern int hugepage_madvise(struct vm_area_struct *vma, + unsigned long *vm_flags, int advice); extern void __vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start, unsigned long end, @@ -143,7 +144,8 @@ static inline int split_huge_page(struct do { } while (0) #define wait_split_huge_page(__anon_vma, __pmd) \ do { } while (0) -static inline int hugepage_madvise(unsigned long *vm_flags, int advice) +static inline int hugepage_madvise(struct vm_area_struct *vma, + unsigned long *vm_flags, int advice) { BUG(); return 0; diff -puN mm/huge_memory.c~thp-khugepaged-make-khugepaged-aware-of-madvise mm/huge_memory.c --- a/mm/huge_memory.c~thp-khugepaged-make-khugepaged-aware-of-madvise +++ a/mm/huge_memory.c @@ -1389,7 +1389,8 @@ out: return ret; } -int hugepage_madvise(unsigned long *vm_flags, int advice) +int hugepage_madvise(struct vm_area_struct *vma, + unsigned long *vm_flags, int advice) { switch (advice) { case MADV_HUGEPAGE: @@ -1404,6 +1405,13 @@ int hugepage_madvise(unsigned long *vm_f return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; + /* + * If the vma become good for khugepaged to scan, + * register it here without waiting a page fault that + * may not happen any time soon. + */ + if (unlikely(khugepaged_enter_vma_merge(vma))) + return -ENOMEM; break; case MADV_NOHUGEPAGE: /* @@ -1417,6 +1425,11 @@ int hugepage_madvise(unsigned long *vm_f return -EINVAL; *vm_flags &= ~VM_HUGEPAGE; *vm_flags |= VM_NOHUGEPAGE; + /* + * Setting VM_NOHUGEPAGE will prevent khugepaged from scanning + * this vma even if we leave the mm registered in khugepaged if + * it got registered before VM_NOHUGEPAGE was set. + */ break; } @@ -1784,7 +1797,8 @@ static void collapse_huge_page(struct mm if (address < hstart || address + HPAGE_PMD_SIZE > hend) goto out; - if (!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) + if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || + (vma->vm_flags & VM_NOHUGEPAGE)) goto out; /* VM_PFNMAP vmas may have vm_ops null but vm_file set */ @@ -2007,8 +2021,9 @@ static unsigned int khugepaged_scan_mm_s break; } - if (!(vma->vm_flags & VM_HUGEPAGE) && - !khugepaged_always()) { + if ((!(vma->vm_flags & VM_HUGEPAGE) && + !khugepaged_always()) || + (vma->vm_flags & VM_NOHUGEPAGE)) { progress++; continue; } diff -puN mm/madvise.c~thp-khugepaged-make-khugepaged-aware-of-madvise mm/madvise.c --- a/mm/madvise.c~thp-khugepaged-make-khugepaged-aware-of-madvise +++ a/mm/madvise.c @@ -73,7 +73,7 @@ static long madvise_behavior(struct vm_a break; case MADV_HUGEPAGE: case MADV_NOHUGEPAGE: - error = hugepage_madvise(&new_flags, behavior); + error = hugepage_madvise(vma, &new_flags, behavior); if (error) goto out; break; _ Patches currently in -mm which might be from aarcange@xxxxxxxxxx are origin.patch thp-add-pagetranscompound.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html