ocfs2: Local alloc window size changeable via mount option
Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.
mount -o localalloc=X /dev/sdX /mntpoint
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index b63bd2d..071fad1 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -72,3 +72,6 @@
it at the default (5 seconds).
Setting it to very large values will improve
performance.
+localalloc=8(*) Allows custom localalloc size in MB. If the value is too
+ large, the fs will silently revert it to the default.
+ Localalloc is not enabled for local mounts.