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| author | Vegard Nossum <vegard.nossum@oracle.com> | 2017-02-27 14:30:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-27 18:43:48 -0800 |
| commit | b279ddc3382426f8e05068de3488a2993f68dc26 (patch) | |
| tree | f1d5eb73fd31c7e34856e8d581e3a9a3f1ffa17d | |
| parent | 388f79345502232d335467e8fa6f8e55a18844e1 (diff) | |
| download | linux-b279ddc3382426f8e05068de3488a2993f68dc26.tar.bz2 | |
mm: clarify mm_struct.mm_{users,count} documentation
Clarify documentation relating to mm_users and mm_count, and switch to
kernel-doc syntax.
Link: http://lkml.kernel.org/r/20161218123229.22952-4-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mm_types.h | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 808751d7b737..4f6d440ad785 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -407,8 +407,27 @@ struct mm_struct { unsigned long task_size; /* size of task vm space */ unsigned long highest_vm_end; /* highest vma end address */ pgd_t * pgd; - atomic_t mm_users; /* How many users with user space? */ - atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ + + /** + * @mm_users: The number of users including userspace. + * + * Use mmget()/mmget_not_zero()/mmput() to modify. When this drops + * to 0 (i.e. when the task exits and there are no other temporary + * reference holders), we also release a reference on @mm_count + * (which may then free the &struct mm_struct if @mm_count also + * drops to 0). + */ + atomic_t mm_users; + + /** + * @mm_count: The number of references to &struct mm_struct + * (@mm_users count as 1). + * + * Use mmgrab()/mmdrop() to modify. When this drops to 0, the + * &struct mm_struct is freed. + */ + atomic_t mm_count; + atomic_long_t nr_ptes; /* PTE page table pages */ #if CONFIG_PGTABLE_LEVELS > 2 atomic_long_t nr_pmds; /* PMD page table pages */ |