diff options
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block-dm | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block-dm b/Documentation/ABI/testing/sysfs-block-dm index 87ca5691e29b..ac4b6fe245d9 100644 --- a/Documentation/ABI/testing/sysfs-block-dm +++ b/Documentation/ABI/testing/sysfs-block-dm @@ -23,3 +23,17 @@ Description: Device-mapper device suspend state. Contains the value 1 while the device is suspended. Otherwise it contains 0. Read-only attribute. Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline +Date: March 2015 +KernelVersion: 4.1 +Contact: dm-devel@redhat.com +Description: Allow control over how long a request that is a + reasonable merge candidate can be queued on the request + queue. The resolution of this deadline is in + microseconds (ranging from 1 to 100000 usecs). + Setting this attribute to 0 (the default) will disable + request-based DM's merge heuristic and associated extra + accounting. This attribute is not applicable to + bio-based DM devices so it will only ever report 0 for + them. |