1 files changed, 7 insertions, 8 deletions
diff --git a/Documentation/vm/locking b/Documentation/vm/locking
index c3ef09ae3bb1..f366fa956179 100644
--- a/Documentation/vm/locking
+++ b/Documentation/vm/locking
@@ -83,19 +83,18 @@ single address space optimization, so that the zap_page_range (from
 vmtruncate) does not lose sending ipi's to cloned threads that might 
 be spawned underneath it and go to user mode to drag in pte's into tlbs.
-swap_list_lock/swap_device_lock
+swap_lock
-------------------------------
+--------------
 The swap devices are chained in priority order from the "swap_list" header. 
 The "swap_list" is used for the round-robin swaphandle allocation strategy.
 The #free swaphandles is maintained in "nr_swap_pages". These two together
-are protected by the swap_list_lock. 
+are protected by the swap_lock.
-The swap_device_lock, which is per swap device, protects the reference 
+The swap_lock also protects all the device reference counts on the
-counts on the corresponding swaphandles, maintained in the "swap_map"
+corresponding swaphandles, maintained in the "swap_map" array, and the
-array, and the "highest_bit" and "lowest_bit" fields.
+"highest_bit" and "lowest_bit" fields.
-Both of these are spinlocks, and are never acquired from intr level. The
+The swap_lock is a spinlock, and is never acquired from intr level.
-locking hierarchy is swap_list_lock -> swap_device_lock.
 To prevent races between swap space deletion or async readahead swapins
 deciding whether a swap handle is being used, ie worthy of being read in

diff --git a/Documentation/vm/locking b/Documentation/vm/locking index c3ef09ae3bb1..f366fa956179 100644 --- a/Documentation/vm/locking +++ b/Documentation/vm/locking
@@ -83,19 +83,18 @@ single address space optimization, so that the zap_page_range (from
83	vmtruncate) does not lose sending ipi's to cloned threads that might	83	vmtruncate) does not lose sending ipi's to cloned threads that might
84	be spawned underneath it and go to user mode to drag in pte's into tlbs.	84	be spawned underneath it and go to user mode to drag in pte's into tlbs.
85		85
86	swap_list_lock/swap_device_lock	86	swap_lock
87	-------------------------------	87	--------------
88	The swap devices are chained in priority order from the "swap_list" header.	88	The swap devices are chained in priority order from the "swap_list" header.
89	The "swap_list" is used for the round-robin swaphandle allocation strategy.	89	The "swap_list" is used for the round-robin swaphandle allocation strategy.
90	The #free swaphandles is maintained in "nr_swap_pages". These two together	90	The #free swaphandles is maintained in "nr_swap_pages". These two together
91	are protected by the swap_list_lock.	91	are protected by the swap_lock.
92		92
93	The swap_device_lock, which is per swap device, protects the reference	93	The swap_lock also protects all the device reference counts on the
94	counts on the corresponding swaphandles, maintained in the "swap_map"	94	corresponding swaphandles, maintained in the "swap_map" array, and the
95	array, and the "highest_bit" and "lowest_bit" fields.	95	"highest_bit" and "lowest_bit" fields.
96		96
97	Both of these are spinlocks, and are never acquired from intr level. The	97	The swap_lock is a spinlock, and is never acquired from intr level.
98	locking hierarchy is swap_list_lock -> swap_device_lock.
99		98
100	To prevent races between swap space deletion or async readahead swapins	99	To prevent races between swap space deletion or async readahead swapins
101	deciding whether a swap handle is being used, ie worthy of being read in	100	deciding whether a swap handle is being used, ie worthy of being read in