[PATCH RFC 3/5] mm/ksm: introduce ksm_madvise_unmerge() helper
flat view
STALE2706d
From: Oleksandr Natalenko <hidden>
Date: 2019-05-16 09:42:48
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - ksm (kernel samepage merging), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Move MADV_UNMERGEABLE part of ksm_madvise() into a dedicated helper since it will be further used for unmerging VMAs forcibly. This does not bring any functional changes. Signed-off-by: Oleksandr Natalenko <redacted> --- include/linux/ksm.h | 2 ++ mm/ksm.c | 32 ++++++++++++++++++++++---------- 2 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index e824b3141677..a91a7cfc87a1 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h@@ -21,6 +21,8 @@ struct mem_cgroup; #ifdef CONFIG_KSM int ksm_madvise_merge(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long *vm_flags); +int ksm_madvise_unmerge(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long *vm_flags); int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags); int __ksm_enter(struct mm_struct *mm);
diff --git a/mm/ksm.c b/mm/ksm.c
index 1fdcf2fbd58d..e0357e25e09f 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c@@ -2478,6 +2478,25 @@ int ksm_madvise_merge(struct mm_struct *mm, struct vm_area_struct *vma, return 0; } +int ksm_madvise_unmerge(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long *vm_flags) +{ + int err; + + if (!(*vm_flags & VM_MERGEABLE)) + return 0; /* just ignore the advice */ + + if (vma->anon_vma) { + err = unmerge_ksm_pages(vma, start, end); + if (err) + return err; + } + + *vm_flags &= ~VM_MERGEABLE; + + return 0; +} + int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags) {
@@ -2492,16 +2511,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, break; case MADV_UNMERGEABLE: - if (!(*vm_flags & VM_MERGEABLE)) - return 0; /* just ignore the advice */ - - if (vma->anon_vma) { - err = unmerge_ksm_pages(vma, start, end); - if (err) - return err; - } - - *vm_flags &= ~VM_MERGEABLE; + err = ksm_madvise_unmerge(vma, start, end, vm_flags); + if (err) + return err; break; }
--
2.21.0