[PATCH] blkback/blkfront patches for v3.11

[PATCH] blkback/blkfront patches for v3.11

[Konrad Rzeszutek Wilk]

Two little fixes for the stable/for-jens-3.10 tree.

One is an addition of the 'max' parameter to the xen-blkfront to alter the
amount of indirect descriptor segments that frontend will try to negotiate.

The other is a fix and moving the parameters for xen-blkback to the
testing directory and also appropiately named file.


 Documentation/ABI/stable/sysfs-bus-xen-backend      | 18 ------------------
 Documentation/ABI/testing/sysfs-driver-xen-blkback  | 17 +++++++++++++++++
 Documentation/ABI/testing/sysfs-driver-xen-blkfront | 10 ++++++++++
 drivers/block/xen-blkfront.c                        |  2 ++
 4 files changed, 29 insertions(+), 18 deletions(-)

[PATCH 1/2] xen-blkfront: Introduce a 'max' module parameter to alter the amount of indirect segments.

[Konrad Rzeszutek Wilk]

The max module parameter (by default 32) is the maximum number of
segments that the frontend will negotiate with the backend for indirect
descriptors.  Higher value means more potential throughput but more
memory usage. The backend picks the minimum of the frontend and its
default backend value.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 Documentation/ABI/testing/sysfs-driver-xen-blkfront | 10 ++++++++++
 drivers/block/xen-blkfront.c                        |  2 ++
 2 files changed, 12 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-xen-blkfront

diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkfront b/Documentation/ABI/testing/sysfs-driver-xen-blkfront
new file mode 100644
index 0000000..c0a6cb7
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkfront
@@ -0,0 +1,10 @@
+What:           /sys/module/xen_blkfront/parameters/max
+Date:           June 2013
+KernelVersion:  3.11
+Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Maximum number of segments that the frontend will negotiate
+                with the backend for indirect descriptors. The default value
+                is 32 - higher value means more potential throughput but more
+                memory usage. The backend picks the minimum of the frontend
+                and its default backend value.
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index cc1e254..618f06c 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -95,6 +95,8 @@ static const struct block_device_operations xlvbd_block_fops;
  */
 
 static unsigned int xen_blkif_max_segments = 32;
+module_param_named(max, xen_blkif_max_segments, int, S_IRUGO);
+MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)");
 
 #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
 
-- 
1.8.1.4

[PATCH 2/2] xen-blkback/sysfs: Move the parameters for the persistent grant features

[Konrad Rzeszutek Wilk]

to a testing subdirectory (as this value should not be baked
for the life-time) and also in an appropiate file.

Also modified the introduction Linux version from 3.10 to 3.11.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 Documentation/ABI/stable/sysfs-bus-xen-backend     | 18 ------------------
 Documentation/ABI/testing/sysfs-driver-xen-blkback | 17 +++++++++++++++++
 2 files changed, 17 insertions(+), 18 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-xen-blkback

diff --git a/Documentation/ABI/stable/sysfs-bus-xen-backend b/Documentation/ABI/stable/sysfs-bus-xen-backend
index 947db11..3d5951c 100644
--- a/Documentation/ABI/stable/sysfs-bus-xen-backend
+++ b/Documentation/ABI/stable/sysfs-bus-xen-backend
@@ -73,21 +73,3 @@ KernelVersion:	3.0
 Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 Description:
                 Number of sectors written by the frontend.
-
-What:           /sys/module/xen_blkback/parameters/max_buffer_pages
-Date:           March 2013
-KernelVersion:  3.10
-Contact:        Roger Pau Monné <roger.pau@citrix.com>
-Description:
-                Maximum number of free pages to keep in each block
-                backend buffer.
-
-What:           /sys/module/xen_blkback/parameters/max_persistent_grants
-Date:           March 2013
-KernelVersion:  3.10
-Contact:        Roger Pau Monné <roger.pau@citrix.com>
-Description:
-                Maximum number of grants to map persistently in
-                blkback. If the frontend tries to use more than
-                max_persistent_grants, the LRU kicks in and starts
-                removing 5% of max_persistent_grants every 100ms.
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
new file mode 100644
index 0000000..8bb43b6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
@@ -0,0 +1,17 @@
+What:           /sys/module/xen_blkback/parameters/max_buffer_pages
+Date:           March 2013
+KernelVersion:  3.11
+Contact:        Roger Pau Monné <roger.pau@citrix.com>
+Description:
+                Maximum number of free pages to keep in each block
+                backend buffer.
+
+What:           /sys/module/xen_blkback/parameters/max_persistent_grants
+Date:           March 2013
+KernelVersion:  3.11
+Contact:        Roger Pau Monné <roger.pau@citrix.com>
+Description:
+                Maximum number of grants to map persistently in
+                blkback. If the frontend tries to use more than
+                max_persistent_grants, the LRU kicks in and starts
+                removing 5% of max_persistent_grants every 100ms.
-- 
1.8.1.4