diff options
| author | Vegard Nossum <vegard.nossum@oracle.com> | 2017-02-08 10:44:13 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-02-09 17:01:39 +1100 |
| commit | 9ef13af6296977af2e8443c1b5b304dd1b50a1e4 (patch) | |
| tree | 3556fd73f888d06ccd14b58f4c9976bbe240e4ee | |
| parent | 99abc1613b1f7ce1b0109c33d3fb6f2b81bac843 (diff) | |
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>
| -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 */ |