From 2c281f54f556e1f3266c8cb104adf9eea7a7b742 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Sat, 22 Apr 2023 23:01:56 +0200 Subject: mm/ksm: move disabling KSM from s390/gmap code to KSM code Let's factor out actual disabling of KSM. The existing "mm->def_flags &= ~VM_MERGEABLE;" was essentially a NOP and can be dropped, because def_flags should never include VM_MERGEABLE. Note that we don't currently prevent re-enabling KSM. This should now be faster in case KSM was never enabled, because we only conditionally iterate all VMAs. Further, it certainly looks cleaner. Link: https://lkml.kernel.org/r/20230422210156.33630-1-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Janosch Frank Acked-by: Stefan Roesch Cc: Christian Borntraeger Cc: Claudio Imbrenda Cc: Heiko Carstens Cc: Johannes Weiner Cc: Michal Hocko Cc: Rik van Riel Cc: Shuah Khan Cc: Sven Schnelle Cc: Vasily Gorbik Signed-off-by: Andrew Morton --- mm/ksm.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'mm/ksm.c') diff --git a/mm/ksm.c b/mm/ksm.c index 823bb3475a68..0156bded3a66 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2628,6 +2628,17 @@ int ksm_disable_merge_any(struct mm_struct *mm) return 0; } +int ksm_disable(struct mm_struct *mm) +{ + mmap_assert_write_locked(mm); + + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) + return 0; + if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) + return ksm_disable_merge_any(mm); + return ksm_del_vmas(mm); +} + int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags) { -- cgit v1.2.3