diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-driver-xen-blkfront | 10 | ||||
| -rw-r--r-- | drivers/block/xen-blkfront.c | 2 |
2 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkfront b/Documentation/ABI/testing/sysfs-driver-xen-blkfront new file mode 100644 index 000000000000..c0a6cb7eb314 --- /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 bac8cf31319b..08bdfc3b2de2 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) |