---

yaml
---
r: 326810
b: refs/heads/master
c: 5dd18b0
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 084cfebc03ede864835594181210b501aa9f1933
+refs/heads/master: 5dd18b0150e6f4eb3a9d06a2621cad8c73a3eccf

trunk/Documentation/block/00-INDEX

@@ -3,21 +3,15 @@
 biodoc.txt
 	- Notes on the Generic Block Layer Rewrite in Linux 2.5
 capability.txt
-	- Generic Block Device Capability (/sys/block/<device>/capability)
-cfq-iosched.txt
-	- CFQ IO scheduler tunables
-data-integrity.txt
-	- Block data integrity
+	- Generic Block Device Capability (/sys/block/<disk>/capability)
 deadline-iosched.txt
 	- Deadline IO scheduler tunables
 ioprio.txt
 	- Block io priorities (in CFQ scheduler)
-queue-sysfs.txt
-	- Queue's sysfs entries
 request.txt
 	- The members of struct request (in include/linux/blkdev.h)
 stat.txt
-	- Block layer statistics in /sys/block/<device>/stat
+	- Block layer statistics in /sys/block/<dev>/stat
 switching-sched.txt
 	- Switching I/O schedulers at runtime
 writeback_cache_control.txt

trunk/Documentation/block/cfq-iosched.txt

@@ -1,14 +1,3 @@
-CFQ (Complete Fairness Queueing)
-===============================
-
-The main aim of CFQ scheduler is to provide a fair allocation of the disk
-I/O bandwidth for all the processes which requests an I/O operation.
-
-CFQ maintains the per process queue for the processes which request I/O
-operation(syncronous requests). In case of asynchronous requests, all the
-requests from all the processes are batched together according to their
-process's I/O priority.
-
 CFQ ioscheduler tunables
 ========================
 
@@ -36,72 +25,6 @@ there are multiple spindles behind single LUN (Host based hardware RAID
 controller or for storage arrays), setting slice_idle=0 might end up in better
 throughput and acceptable latencies.
 
-back_seek_max
--------------
-This specifies, given in Kbytes, the maximum "distance" for backward seeking.
-The distance is the amount of space from the current head location to the
-sectors that are backward in terms of distance.
-
-This parameter allows the scheduler to anticipate requests in the "backward"
-direction and consider them as being the "next" if they are within this
-distance from the current head location.
-
-back_seek_penalty
------------------
-This parameter is used to compute the cost of backward seeking. If the
-backward distance of request is just 1/back_seek_penalty from a "front"
-request, then the seeking cost of two requests is considered equivalent.
-
-So scheduler will not bias toward one or the other request (otherwise scheduler
-will bias toward front request). Default value of back_seek_penalty is 2.
-
-fifo_expire_async
------------------
-This parameter is used to set the timeout of asynchronous requests. Default
-value of this is 248ms.
-
-fifo_expire_sync
-----------------
-This parameter is used to set the timeout of synchronous requests. Default
-value of this is 124ms. In case to favor synchronous requests over asynchronous
-one, this value should be decreased relative to fifo_expire_async.
-
-slice_async
------------
-This parameter is same as of slice_sync but for asynchronous queue. The
-default value is 40ms.
-
-slice_async_rq
---------------
-This parameter is used to limit the dispatching of asynchronous request to
-device request queue in queue's slice time. The maximum number of request that
-are allowed to be dispatched also depends upon the io priority. Default value
-for this is 2.
-
-slice_sync
-----------
-When a queue is selected for execution, the queues IO requests are only
-executed for a certain amount of time(time_slice) before switching to another
-queue. This parameter is used to calculate the time slice of synchronous
-queue.
-
-time_slice is computed using the below equation:-
-time_slice = slice_sync + (slice_sync/5 * (4 - prio)). To increase the
-time_slice of synchronous queue, increase the value of slice_sync. Default
-value is 100ms.
-
-quantum
--------
-This specifies the number of request dispatched to the device queue. In a
-queue's time slice, a request will not be dispatched if the number of request
-in the device exceeds this parameter. This parameter is used for synchronous
-request.
-
-In case of storage with several disk, this setting can limit the parallel
-processing of request. Therefore, increasing the value can imporve the
-performace although this can cause the latency of some I/O to increase due
-to more number of requests.
-
 CFQ IOPS Mode for group scheduling
 ===================================
 Basic CFQ design is to provide priority based time slices. Higher priority

trunk/Documentation/block/queue-sysfs.txt

@@ -9,71 +9,20 @@ These files are the ones found in the /sys/block/xxx/queue/ directory.
 Files denoted with a RO postfix are readonly and the RW postfix means
 read-write.
 
-add_random (RW)
-----------------
-This file allows to trun off the disk entropy contribution. Default
-value of this file is '1'(on).
-
-discard_granularity (RO)
------------------------
-This shows the size of internal allocation of the device in bytes, if
-reported by the device. A value of '0' means device does not support
-the discard functionality.
-
-discard_max_bytes (RO)
-----------------------
-Devices that support discard functionality may have internal limits on
-the number of bytes that can be trimmed or unmapped in a single operation.
-The discard_max_bytes parameter is set by the device driver to the maximum
-number of bytes that can be discarded in a single operation. Discard
-requests issued to the device must not exceed this limit. A discard_max_bytes
-value of 0 means that the device does not support discard functionality.
-
-discard_zeroes_data (RO)
-------------------------
-When read, this file will show if the discarded block are zeroed by the
-device or not. If its value is '1' the blocks are zeroed otherwise not.
-
 hw_sector_size (RO)
 -------------------
 This is the hardware sector size of the device, in bytes.
 
-iostats (RW)
--------------
-This file is used to control (on/off) the iostats accounting of the
-disk.
-
-logical_block_size (RO)
------------------------
-This is the logcal block size of the device, in bytes.
-
 max_hw_sectors_kb (RO)
 ----------------------
 This is the maximum number of kilobytes supported in a single data transfer.
 
-max_integrity_segments (RO)
----------------------------
-When read, this file shows the max limit of integrity segments as
-set by block layer which a hardware controller can handle.
-
 max_sectors_kb (RW)
 -------------------
 This is the maximum number of kilobytes that the block layer will allow
 for a filesystem request. Must be smaller than or equal to the maximum
 size allowed by the hardware.
 
-max_segments (RO)
------------------
-Maximum number of segments of the device.
-
-max_segment_size (RO)
----------------------
-Maximum segment size of the device.
-
-minimum_io_size (RO)
---------------------
-This is the smallest preferred io size reported by the device.
-
 nomerges (RW)
 -------------
 This enables the user to disable the lookup logic involved with IO
@@ -96,24 +45,11 @@ per-block-cgroup request pool.  IOW, if there are N block cgroups,
 each request queue may have upto N request pools, each independently
 regulated by nr_requests.
 
-optimal_io_size (RO)
---------------------
-This is the optimal io size reported by the device.
-
-physical_block_size (RO)
-------------------------
-This is the physical block size of device, in bytes.
-
 read_ahead_kb (RW)
 ------------------
 Maximum number of kilobytes to read-ahead for filesystems on this block
 device.
 
-rotational (RW)
----------------
-This file is used to stat if the device is of rotational type or
-non-rotational type.
-
 rq_affinity (RW)
 ----------------
 If this option is '1', the block layer will migrate request completions to the