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 /include | |
| parent | 83cde9e8ba95d180eaefefe834958fbf7008cf39 (diff) | |
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 'include')
| -rw-r--r-- | include/linux/fs.h | 7 | ||||
| -rw-r--r-- | include/linux/mmu_notifier.h | 2 |
2 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index bd0a1b2f3c02..6abcd0b72ae0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -18,6 +18,7 @@ #include <linux/pid.h> #include <linux/bug.h> #include <linux/mutex.h> +#include <linux/rwsem.h> #include <linux/capability.h> #include <linux/semaphore.h> #include <linux/fiemap.h> @@ -401,7 +402,7 @@ struct address_space { atomic_t i_mmap_writable;/* count VM_SHARED mappings */ struct rb_root i_mmap; /* tree of private and shared mappings */ struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */ - struct mutex i_mmap_mutex; /* protect tree, count, list */ + struct rw_semaphore i_mmap_rwsem; /* protect tree, count, list */ /* Protected by tree_lock together with the radix tree */ unsigned long nrpages; /* number of total pages */ unsigned long nrshadows; /* number of shadow entries */ @@ -469,12 +470,12 @@ int mapping_tagged(struct address_space *mapping, int tag); static inline void i_mmap_lock_write(struct address_space *mapping) { - mutex_lock(&mapping->i_mmap_mutex); + down_write(&mapping->i_mmap_rwsem); } static inline void i_mmap_unlock_write(struct address_space *mapping) { - mutex_unlock(&mapping->i_mmap_mutex); + up_write(&mapping->i_mmap_rwsem); } /* diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 88787bb4b3b9..ab8564b03468 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -154,7 +154,7 @@ struct mmu_notifier_ops { * Therefore notifier chains can only be traversed when either * * 1. mmap_sem is held. - * 2. One of the reverse map locks is held (i_mmap_mutex or anon_vma->rwsem). + * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem). * 3. No other concurrent thread can access the list (release) */ struct mmu_notifier { |