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authorMike Rapoport <rppt@linux.vnet.ibm.com>2018-03-21 21:22:40 +0200
committerJonathan Corbet <corbet@lwn.net>2018-04-16 14:18:14 -0600
commit543199823345a3d8532d41f203477742cb2b06d8 (patch)
tree84c0a79e086df3a2aec3ae6e8709a89be01945ae /Documentation/vm
parentd18edf52f42b6e7453593738a86c288782c79fe3 (diff)
docs/vm: swap_numa.txt: convert to ReST format
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/vm')
-rw-r--r--Documentation/vm/swap_numa.txt55
1 files changed, 33 insertions, 22 deletions
diff --git a/Documentation/vm/swap_numa.txt b/Documentation/vm/swap_numa.txt
index d5960c9124f5..e0466f2db8fa 100644
--- a/Documentation/vm/swap_numa.txt
+++ b/Documentation/vm/swap_numa.txt
@@ -1,5 +1,8 @@
+.. _swap_numa:
+
+===========================================
Automatically bind swap device to numa node
--------------------------------------------
+===========================================
If the system has more than one swap device and swap device has the node
information, we can make use of this information to decide which swap
@@ -7,15 +10,16 @@ device to use in get_swap_pages() to get better performance.
How to use this feature
------------------------
+=======================
Swap device has priority and that decides the order of it to be used. To make
use of automatically binding, there is no need to manipulate priority settings
for swap devices. e.g. on a 2 node machine, assume 2 swap devices swapA and
swapB, with swapA attached to node 0 and swapB attached to node 1, are going
-to be swapped on. Simply swapping them on by doing:
-# swapon /dev/swapA
-# swapon /dev/swapB
+to be swapped on. Simply swapping them on by doing::
+
+ # swapon /dev/swapA
+ # swapon /dev/swapB
Then node 0 will use the two swap devices in the order of swapA then swapB and
node 1 will use the two swap devices in the order of swapB then swapA. Note
@@ -24,32 +28,39 @@ that the order of them being swapped on doesn't matter.
A more complex example on a 4 node machine. Assume 6 swap devices are going to
be swapped on: swapA and swapB are attached to node 0, swapC is attached to
node 1, swapD and swapE are attached to node 2 and swapF is attached to node3.
-The way to swap them on is the same as above:
-# swapon /dev/swapA
-# swapon /dev/swapB
-# swapon /dev/swapC
-# swapon /dev/swapD
-# swapon /dev/swapE
-# swapon /dev/swapF
-
-Then node 0 will use them in the order of:
-swapA/swapB -> swapC -> swapD -> swapE -> swapF
+The way to swap them on is the same as above::
+
+ # swapon /dev/swapA
+ # swapon /dev/swapB
+ # swapon /dev/swapC
+ # swapon /dev/swapD
+ # swapon /dev/swapE
+ # swapon /dev/swapF
+
+Then node 0 will use them in the order of::
+
+ swapA/swapB -> swapC -> swapD -> swapE -> swapF
+
swapA and swapB will be used in a round robin mode before any other swap device.
-node 1 will use them in the order of:
-swapC -> swapA -> swapB -> swapD -> swapE -> swapF
+node 1 will use them in the order of::
+
+ swapC -> swapA -> swapB -> swapD -> swapE -> swapF
+
+node 2 will use them in the order of::
+
+ swapD/swapE -> swapA -> swapB -> swapC -> swapF
-node 2 will use them in the order of:
-swapD/swapE -> swapA -> swapB -> swapC -> swapF
Similaly, swapD and swapE will be used in a round robin mode before any
other swap devices.
-node 3 will use them in the order of:
-swapF -> swapA -> swapB -> swapC -> swapD -> swapE
+node 3 will use them in the order of::
+
+ swapF -> swapA -> swapB -> swapC -> swapD -> swapE
Implementation details
-----------------------
+======================
The current code uses a priority based list, swap_avail_list, to decide
which swap device to use and if multiple swap devices share the same