After fork, the new process will get incorrect hugetlb_usage. The reason is dup_mm copies old_mm to the new one and mm_init does not init hugetlb_usage. Fix this by adding hugetlb_count_init in mm_init. Signed-off-by: Liu Zixian <liuzixian4@xxxxxxxxxx> --- include/linux/hugetlb.h | 5 +++++ kernel/fork.c | 3 +++ 2 files changed, 8 insertions(+) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index f7ca1a387..66ceabd66 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -858,6 +858,11 @@ static inline spinlock_t *huge_pte_lockptr(struct hstate *h, void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm); +static inline void hugetlb_count_init(struct mm_struct *mm) +{ + atomic_long_set(&mm->hugetlb_usage, 0); +} + static inline void hugetlb_count_add(long l, struct mm_struct *mm) { atomic_long_add(l, &mm->hugetlb_usage); diff --git a/kernel/fork.c b/kernel/fork.c index bc94b2cc5..a9380081a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1050,6 +1050,9 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->pmd_huge_pte = NULL; #endif mm_init_uprobes_state(mm); +#ifdef CONFIG_HUGETLB_PAGE + hugetlb_count_init(mm); +#endif if (current->mm) { mm->flags = current->mm->flags & MMF_INIT_MASK; -- 2.18.1