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author | Davidlohr Bueso <dave@stgolabs.net> | 2014-12-12 16:54:24 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:45 -0800 |
commit | c8c06efa8b552608493b7066c234cfa82c47fcea (patch) | |
tree | 7e206c669149766fb5a77a3ef85cdd4fac63be78 /mm/mremap.c | |
parent | 83cde9e8ba95d180eaefefe834958fbf7008cf39 (diff) | |
download | op-kernel-dev-c8c06efa8b552608493b7066c234cfa82c47fcea.zip op-kernel-dev-c8c06efa8b552608493b7066c234cfa82c47fcea.tar.gz |
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/mremap.c')
-rw-r--r-- | mm/mremap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 426b448..84aa36f 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -99,7 +99,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, spinlock_t *old_ptl, *new_ptl; /* - * When need_rmap_locks is true, we take the i_mmap_mutex and anon_vma + * When need_rmap_locks is true, we take the i_mmap_rwsem and anon_vma * locks to ensure that rmap will always observe either the old or the * new ptes. This is the easiest way to avoid races with * truncate_pagecache(), page migration, etc... |