diff options
Diffstat (limited to 'mm/ksm.c')
| -rw-r--r-- | mm/ksm.c | 14 |
1 files changed, 13 insertions, 1 deletions
@@ -32,7 +32,6 @@ #include <linux/mmu_notifier.h> #include <linux/ksm.h> -#include <asm/tlb.h> #include <asm/tlbflush.h> /* @@ -285,6 +284,19 @@ static inline int in_stable_tree(struct rmap_item *rmap_item) } /* + * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's + * page tables after it has passed through ksm_exit() - which, if necessary, + * takes mmap_sem briefly to serialize against them. ksm_exit() does not set + * a special flag: they can just back out as soon as mm_users goes to zero. + * ksm_test_exit() is used throughout to make this test for exit: in some + * places for correctness, in some places just to avoid unnecessary work. + */ +static inline bool ksm_test_exit(struct mm_struct *mm) +{ + return atomic_read(&mm->mm_users) == 0; +} + +/* * We use break_ksm to break COW on a ksm page: it's a stripped down * * if (get_user_pages(current, mm, addr, 1, 1, 1, &page, NULL) == 1) |