aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-pci12
-rw-r--r--Documentation/block/00-INDEX10
-rw-r--r--Documentation/block/cfq-iosched.txt77
-rw-r--r--Documentation/block/queue-sysfs.txt64
-rw-r--r--Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt8
-rw-r--r--Documentation/feature-removal-schedule.txt2
-rw-r--r--Documentation/i2c/busses/i2c-i8011
-rw-r--r--Documentation/watchdog/src/watchdog-test.c2
8 files changed, 168 insertions, 8 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 34f51100f029..dff1f48d252d 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -210,3 +210,15 @@ Users:
210 firmware assigned instance number of the PCI 210 firmware assigned instance number of the PCI
211 device that can help in understanding the firmware 211 device that can help in understanding the firmware
212 intended order of the PCI device. 212 intended order of the PCI device.
213
214What: /sys/bus/pci/devices/.../d3cold_allowed
215Date: July 2012
216Contact: Huang Ying <ying.huang@intel.com>
217Description:
218 d3cold_allowed is bit to control whether the corresponding PCI
219 device can be put into D3Cold state. If it is cleared, the
220 device will never be put into D3Cold state. If it is set, the
221 device may be put into D3Cold state if other requirements are
222 satisfied too. Reading this attribute will show the current
223 value of d3cold_allowed bit. Writing this attribute will set
224 the value of d3cold_allowed bit.
diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX
index d111e3b23db0..d18ecd827c40 100644
--- a/Documentation/block/00-INDEX
+++ b/Documentation/block/00-INDEX
@@ -3,15 +3,21 @@
3biodoc.txt 3biodoc.txt
4 - Notes on the Generic Block Layer Rewrite in Linux 2.5 4 - Notes on the Generic Block Layer Rewrite in Linux 2.5
5capability.txt 5capability.txt
6 - Generic Block Device Capability (/sys/block/<disk>/capability) 6 - Generic Block Device Capability (/sys/block/<device>/capability)
7cfq-iosched.txt
8 - CFQ IO scheduler tunables
9data-integrity.txt
10 - Block data integrity
7deadline-iosched.txt 11deadline-iosched.txt
8 - Deadline IO scheduler tunables 12 - Deadline IO scheduler tunables
9ioprio.txt 13ioprio.txt
10 - Block io priorities (in CFQ scheduler) 14 - Block io priorities (in CFQ scheduler)
15queue-sysfs.txt
16 - Queue's sysfs entries
11request.txt 17request.txt
12 - The members of struct request (in include/linux/blkdev.h) 18 - The members of struct request (in include/linux/blkdev.h)
13stat.txt 19stat.txt
14 - Block layer statistics in /sys/block/<dev>/stat 20 - Block layer statistics in /sys/block/<device>/stat
15switching-sched.txt 21switching-sched.txt
16 - Switching I/O schedulers at runtime 22 - Switching I/O schedulers at runtime
17writeback_cache_control.txt 23writeback_cache_control.txt
diff --git a/Documentation/block/cfq-iosched.txt b/Documentation/block/cfq-iosched.txt
index 6d670f570451..d89b4fe724d7 100644
--- a/Documentation/block/cfq-iosched.txt
+++ b/Documentation/block/cfq-iosched.txt
@@ -1,3 +1,14 @@
1CFQ (Complete Fairness Queueing)
2===============================
3
4The main aim of CFQ scheduler is to provide a fair allocation of the disk
5I/O bandwidth for all the processes which requests an I/O operation.
6
7CFQ maintains the per process queue for the processes which request I/O
8operation(syncronous requests). In case of asynchronous requests, all the
9requests from all the processes are batched together according to their
10process's I/O priority.
11
1CFQ ioscheduler tunables 12CFQ ioscheduler tunables
2======================== 13========================
3 14
@@ -25,6 +36,72 @@ there are multiple spindles behind single LUN (Host based hardware RAID
25controller or for storage arrays), setting slice_idle=0 might end up in better 36controller or for storage arrays), setting slice_idle=0 might end up in better
26throughput and acceptable latencies. 37throughput and acceptable latencies.
27 38
39back_seek_max
40-------------
41This specifies, given in Kbytes, the maximum "distance" for backward seeking.
42The distance is the amount of space from the current head location to the
43sectors that are backward in terms of distance.
44
45This parameter allows the scheduler to anticipate requests in the "backward"
46direction and consider them as being the "next" if they are within this
47distance from the current head location.
48
49back_seek_penalty
50-----------------
51This parameter is used to compute the cost of backward seeking. If the
52backward distance of request is just 1/back_seek_penalty from a "front"
53request, then the seeking cost of two requests is considered equivalent.
54
55So scheduler will not bias toward one or the other request (otherwise scheduler
56will bias toward front request). Default value of back_seek_penalty is 2.
57
58fifo_expire_async
59-----------------
60This parameter is used to set the timeout of asynchronous requests. Default
61value of this is 248ms.
62
63fifo_expire_sync
64----------------
65This parameter is used to set the timeout of synchronous requests. Default
66value of this is 124ms. In case to favor synchronous requests over asynchronous
67one, this value should be decreased relative to fifo_expire_async.
68
69slice_async
70-----------
71This parameter is same as of slice_sync but for asynchronous queue. The
72default value is 40ms.
73
74slice_async_rq
75--------------
76This parameter is used to limit the dispatching of asynchronous request to
77device request queue in queue's slice time. The maximum number of request that
78are allowed to be dispatched also depends upon the io priority. Default value
79for this is 2.
80
81slice_sync
82----------
83When a queue is selected for execution, the queues IO requests are only
84executed for a certain amount of time(time_slice) before switching to another
85queue. This parameter is used to calculate the time slice of synchronous
86queue.
87
88time_slice is computed using the below equation:-
89time_slice = slice_sync + (slice_sync/5 * (4 - prio)). To increase the
90time_slice of synchronous queue, increase the value of slice_sync. Default
91value is 100ms.
92
93quantum
94-------
95This specifies the number of request dispatched to the device queue. In a
96queue's time slice, a request will not be dispatched if the number of request
97in the device exceeds this parameter. This parameter is used for synchronous
98request.
99
100In case of storage with several disk, this setting can limit the parallel
101processing of request. Therefore, increasing the value can imporve the
102performace although this can cause the latency of some I/O to increase due
103to more number of requests.
104
28CFQ IOPS Mode for group scheduling 105CFQ IOPS Mode for group scheduling
29=================================== 106===================================
30Basic CFQ design is to provide priority based time slices. Higher priority 107Basic CFQ design is to provide priority based time slices. Higher priority
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 6518a55273e7..e54ac1d53403 100644
--- a/Documentation/block/queue-sysfs.txt
+++ b/Documentation/block/queue-sysfs.txt
@@ -9,20 +9,71 @@ These files are the ones found in the /sys/block/xxx/queue/ directory.
9Files denoted with a RO postfix are readonly and the RW postfix means 9Files denoted with a RO postfix are readonly and the RW postfix means
10read-write. 10read-write.
11 11
12add_random (RW)
13----------------
14This file allows to trun off the disk entropy contribution. Default
15value of this file is '1'(on).
16
17discard_granularity (RO)
18-----------------------
19This shows the size of internal allocation of the device in bytes, if
20reported by the device. A value of '0' means device does not support
21the discard functionality.
22
23discard_max_bytes (RO)
24----------------------
25Devices that support discard functionality may have internal limits on
26the number of bytes that can be trimmed or unmapped in a single operation.
27The discard_max_bytes parameter is set by the device driver to the maximum
28number of bytes that can be discarded in a single operation. Discard
29requests issued to the device must not exceed this limit. A discard_max_bytes
30value of 0 means that the device does not support discard functionality.
31
32discard_zeroes_data (RO)
33------------------------
34When read, this file will show if the discarded block are zeroed by the
35device or not. If its value is '1' the blocks are zeroed otherwise not.
36
12hw_sector_size (RO) 37hw_sector_size (RO)
13------------------- 38-------------------
14This is the hardware sector size of the device, in bytes. 39This is the hardware sector size of the device, in bytes.
15 40
41iostats (RW)
42-------------
43This file is used to control (on/off) the iostats accounting of the
44disk.
45
46logical_block_size (RO)
47-----------------------
48This is the logcal block size of the device, in bytes.
49
16max_hw_sectors_kb (RO) 50max_hw_sectors_kb (RO)
17---------------------- 51----------------------
18This is the maximum number of kilobytes supported in a single data transfer. 52This is the maximum number of kilobytes supported in a single data transfer.
19 53
54max_integrity_segments (RO)
55---------------------------
56When read, this file shows the max limit of integrity segments as
57set by block layer which a hardware controller can handle.
58
20max_sectors_kb (RW) 59max_sectors_kb (RW)
21------------------- 60-------------------
22This is the maximum number of kilobytes that the block layer will allow 61This is the maximum number of kilobytes that the block layer will allow
23for a filesystem request. Must be smaller than or equal to the maximum 62for a filesystem request. Must be smaller than or equal to the maximum
24size allowed by the hardware. 63size allowed by the hardware.
25 64
65max_segments (RO)
66-----------------
67Maximum number of segments of the device.
68
69max_segment_size (RO)
70---------------------
71Maximum segment size of the device.
72
73minimum_io_size (RO)
74--------------------
75This is the smallest preferred io size reported by the device.
76
26nomerges (RW) 77nomerges (RW)
27------------- 78-------------
28This enables the user to disable the lookup logic involved with IO 79This enables the user to disable the lookup logic involved with IO
@@ -45,11 +96,24 @@ per-block-cgroup request pool. IOW, if there are N block cgroups,
45each request queue may have upto N request pools, each independently 96each request queue may have upto N request pools, each independently
46regulated by nr_requests. 97regulated by nr_requests.
47 98
99optimal_io_size (RO)
100--------------------
101This is the optimal io size reported by the device.
102
103physical_block_size (RO)
104------------------------
105This is the physical block size of device, in bytes.
106
48read_ahead_kb (RW) 107read_ahead_kb (RW)
49------------------ 108------------------
50Maximum number of kilobytes to read-ahead for filesystems on this block 109Maximum number of kilobytes to read-ahead for filesystems on this block
51device. 110device.
52 111
112rotational (RW)
113---------------
114This file is used to stat if the device is of rotational type or
115non-rotational type.
116
53rq_affinity (RW) 117rq_affinity (RW)
54---------------- 118----------------
55If this option is '1', the block layer will migrate request completions to the 119If this option is '1', the block layer will migrate request completions to the
diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
index 70cd49b1caa8..1dd622546d06 100644
--- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
+++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
@@ -10,8 +10,8 @@ Required properties:
10- compatible : Should be "fsl,<chip>-esdhc" 10- compatible : Should be "fsl,<chip>-esdhc"
11 11
12Optional properties: 12Optional properties:
13- fsl,cd-internal : Indicate to use controller internal card detection 13- fsl,cd-controller : Indicate to use controller internal card detection
14- fsl,wp-internal : Indicate to use controller internal write protection 14- fsl,wp-controller : Indicate to use controller internal write protection
15 15
16Examples: 16Examples:
17 17
@@ -19,8 +19,8 @@ esdhc@70004000 {
19 compatible = "fsl,imx51-esdhc"; 19 compatible = "fsl,imx51-esdhc";
20 reg = <0x70004000 0x4000>; 20 reg = <0x70004000 0x4000>;
21 interrupts = <1>; 21 interrupts = <1>;
22 fsl,cd-internal; 22 fsl,cd-controller;
23 fsl,wp-internal; 23 fsl,wp-controller;
24}; 24};
25 25
26esdhc@70008000 { 26esdhc@70008000 {
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index b9aa38bca04c..32de36c3def1 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -568,7 +568,7 @@ Why: KVM tracepoints provide mostly equivalent information in a much more
568---------------------------- 568----------------------------
569 569
570What: at91-mci driver ("CONFIG_MMC_AT91") 570What: at91-mci driver ("CONFIG_MMC_AT91")
571When: 3.7 571When: 3.8
572Why: There are two mci drivers: at91-mci and atmel-mci. The PDC support 572Why: There are two mci drivers: at91-mci and atmel-mci. The PDC support
573 was added to atmel-mci as a first step to support more chips. 573 was added to atmel-mci as a first step to support more chips.
574 Then at91-mci was kept only for old IP versions (on at91rm9200 and 574 Then at91-mci was kept only for old IP versions (on at91rm9200 and
diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801
index 615142da4ef6..157416e78cc4 100644
--- a/Documentation/i2c/busses/i2c-i801
+++ b/Documentation/i2c/busses/i2c-i801
@@ -21,6 +21,7 @@ Supported adapters:
21 * Intel DH89xxCC (PCH) 21 * Intel DH89xxCC (PCH)
22 * Intel Panther Point (PCH) 22 * Intel Panther Point (PCH)
23 * Intel Lynx Point (PCH) 23 * Intel Lynx Point (PCH)
24 * Intel Lynx Point-LP (PCH)
24 Datasheets: Publicly available at the Intel website 25 Datasheets: Publicly available at the Intel website
25 26
26On Intel Patsburg and later chipsets, both the normal host SMBus controller 27On Intel Patsburg and later chipsets, both the normal host SMBus controller
diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c
index 73ff5cc93e05..3da822967ee0 100644
--- a/Documentation/watchdog/src/watchdog-test.c
+++ b/Documentation/watchdog/src/watchdog-test.c
@@ -31,7 +31,7 @@ static void keep_alive(void)
31 * or "-e" to enable the card. 31 * or "-e" to enable the card.
32 */ 32 */
33 33
34void term(int sig) 34static void term(int sig)
35{ 35{
36 close(fd); 36 close(fd);
37 fprintf(stderr, "Stopping watchdog ticks...\n"); 37 fprintf(stderr, "Stopping watchdog ticks...\n");