diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2014-12-12 16:54:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:45 -0800 |
| commit | c8c06efa8b552608493b7066c234cfa82c47fcea (patch) | |
| tree | 7e206c669149766fb5a77a3ef85cdd4fac63be78 /mm/mmap.c | |
| parent | 83cde9e8ba95d180eaefefe834958fbf7008cf39 (diff) | |
| download | lwn-c8c06efa8b552608493b7066c234cfa82c47fcea.tar.gz lwn-c8c06efa8b552608493b7066c234cfa82c47fcea.zip | |
mm: convert i_mmap_mutex to rwsem
The i_mmap_mutex is a close cousin of the anon vma lock, both protecting
similar data, one for file backed pages and the other for anon memory. To
this end, this lock can also be a rwsem. In addition, there are some
important opportunities to share the lock when there are no tree
modifications.
This conversion is straightforward. For now, all users take the write
lock.
[sfr@canb.auug.org.au: update fremap.c]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index ecd6ecf48778..0d84b2f86f3b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -232,7 +232,7 @@ error: } /* - * Requires inode->i_mapping->i_mmap_mutex + * Requires inode->i_mapping->i_mmap_rwsem */ static void __remove_shared_vm_struct(struct vm_area_struct *vma, struct file *file, struct address_space *mapping) @@ -2791,7 +2791,7 @@ void exit_mmap(struct mm_struct *mm) /* Insert vm structure into process list sorted by address * and into the inode's i_mmap tree. If vm_file is non-NULL - * then i_mmap_mutex is taken here. + * then i_mmap_rwsem is taken here. */ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma) { @@ -3086,7 +3086,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) */ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); - mutex_lock_nest_lock(&mapping->i_mmap_mutex, &mm->mmap_sem); + down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_sem); } } @@ -3113,7 +3113,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) * vma in this mm is backed by the same anon_vma or address_space. * * We can take all the locks in random order because the VM code - * taking i_mmap_mutex or anon_vma->rwsem outside the mmap_sem never + * taking i_mmap_rwsem or anon_vma->rwsem outside the mmap_sem never * takes more than one of them in a row. Secondly we're protected * against a concurrent mm_take_all_locks() by the mm_all_locks_mutex. * |