diff options
Diffstat (limited to 'Documentation')
19 files changed, 430 insertions, 63 deletions
diff --git a/Documentation/PCI/PCI-DMA-mapping.txt b/Documentation/DMA-API-HOWTO.txt index 52618ab069ad..52618ab069ad 100644 --- a/Documentation/PCI/PCI-DMA-mapping.txt +++ b/Documentation/DMA-API-HOWTO.txt | |||
diff --git a/Documentation/DocBook/tracepoint.tmpl b/Documentation/DocBook/tracepoint.tmpl index 8bca1d5cec09..e8473eae2a20 100644 --- a/Documentation/DocBook/tracepoint.tmpl +++ b/Documentation/DocBook/tracepoint.tmpl | |||
@@ -16,6 +16,15 @@ | |||
16 | </address> | 16 | </address> |
17 | </affiliation> | 17 | </affiliation> |
18 | </author> | 18 | </author> |
19 | <author> | ||
20 | <firstname>William</firstname> | ||
21 | <surname>Cohen</surname> | ||
22 | <affiliation> | ||
23 | <address> | ||
24 | <email>wcohen@redhat.com</email> | ||
25 | </address> | ||
26 | </affiliation> | ||
27 | </author> | ||
19 | </authorgroup> | 28 | </authorgroup> |
20 | 29 | ||
21 | <legalnotice> | 30 | <legalnotice> |
@@ -91,4 +100,8 @@ | |||
91 | !Iinclude/trace/events/signal.h | 100 | !Iinclude/trace/events/signal.h |
92 | </chapter> | 101 | </chapter> |
93 | 102 | ||
103 | <chapter id="block"> | ||
104 | <title>Block IO</title> | ||
105 | !Iinclude/trace/events/block.h | ||
106 | </chapter> | ||
94 | </book> | 107 | </book> |
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 6fab97ea7e6b..508b5b2b0289 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt | |||
@@ -1162,8 +1162,8 @@ where a driver received a request ala this before: | |||
1162 | 1162 | ||
1163 | As mentioned, there is no virtual mapping of a bio. For DMA, this is | 1163 | As mentioned, there is no virtual mapping of a bio. For DMA, this is |
1164 | not a problem as the driver probably never will need a virtual mapping. | 1164 | not a problem as the driver probably never will need a virtual mapping. |
1165 | Instead it needs a bus mapping (pci_map_page for a single segment or | 1165 | Instead it needs a bus mapping (dma_map_page for a single segment or |
1166 | use blk_rq_map_sg for scatter gather) to be able to ship it to the driver. For | 1166 | use dma_map_sg for scatter gather) to be able to ship it to the driver. For |
1167 | PIO drivers (or drivers that need to revert to PIO transfer once in a | 1167 | PIO drivers (or drivers that need to revert to PIO transfer once in a |
1168 | while (IDE for example)), where the CPU is doing the actual data | 1168 | while (IDE for example)), where the CPU is doing the actual data |
1169 | transfer a virtual mapping is needed. If the driver supports highmem I/O, | 1169 | transfer a virtual mapping is needed. If the driver supports highmem I/O, |
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index f8bc802d70b9..3a6aecd078ba 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt | |||
@@ -340,7 +340,7 @@ Note: | |||
340 | 5.3 swappiness | 340 | 5.3 swappiness |
341 | Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. | 341 | Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. |
342 | 342 | ||
343 | Following cgroups' swapiness can't be changed. | 343 | Following cgroups' swappiness can't be changed. |
344 | - root cgroup (uses /proc/sys/vm/swappiness). | 344 | - root cgroup (uses /proc/sys/vm/swappiness). |
345 | - a cgroup which uses hierarchy and it has child cgroup. | 345 | - a cgroup which uses hierarchy and it has child cgroup. |
346 | - a cgroup which uses hierarchy and not the root of hierarchy. | 346 | - a cgroup which uses hierarchy and not the root of hierarchy. |
diff --git a/Documentation/circular-buffers.txt b/Documentation/circular-buffers.txt new file mode 100644 index 000000000000..8117e5bf6065 --- /dev/null +++ b/Documentation/circular-buffers.txt | |||
@@ -0,0 +1,234 @@ | |||
1 | ================ | ||
2 | CIRCULAR BUFFERS | ||
3 | ================ | ||
4 | |||
5 | By: David Howells <dhowells@redhat.com> | ||
6 | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | ||
7 | |||
8 | |||
9 | Linux provides a number of features that can be used to implement circular | ||
10 | buffering. There are two sets of such features: | ||
11 | |||
12 | (1) Convenience functions for determining information about power-of-2 sized | ||
13 | buffers. | ||
14 | |||
15 | (2) Memory barriers for when the producer and the consumer of objects in the | ||
16 | buffer don't want to share a lock. | ||
17 | |||
18 | To use these facilities, as discussed below, there needs to be just one | ||
19 | producer and just one consumer. It is possible to handle multiple producers by | ||
20 | serialising them, and to handle multiple consumers by serialising them. | ||
21 | |||
22 | |||
23 | Contents: | ||
24 | |||
25 | (*) What is a circular buffer? | ||
26 | |||
27 | (*) Measuring power-of-2 buffers. | ||
28 | |||
29 | (*) Using memory barriers with circular buffers. | ||
30 | - The producer. | ||
31 | - The consumer. | ||
32 | |||
33 | |||
34 | ========================== | ||
35 | WHAT IS A CIRCULAR BUFFER? | ||
36 | ========================== | ||
37 | |||
38 | First of all, what is a circular buffer? A circular buffer is a buffer of | ||
39 | fixed, finite size into which there are two indices: | ||
40 | |||
41 | (1) A 'head' index - the point at which the producer inserts items into the | ||
42 | buffer. | ||
43 | |||
44 | (2) A 'tail' index - the point at which the consumer finds the next item in | ||
45 | the buffer. | ||
46 | |||
47 | Typically when the tail pointer is equal to the head pointer, the buffer is | ||
48 | empty; and the buffer is full when the head pointer is one less than the tail | ||
49 | pointer. | ||
50 | |||
51 | The head index is incremented when items are added, and the tail index when | ||
52 | items are removed. The tail index should never jump the head index, and both | ||
53 | indices should be wrapped to 0 when they reach the end of the buffer, thus | ||
54 | allowing an infinite amount of data to flow through the buffer. | ||
55 | |||
56 | Typically, items will all be of the same unit size, but this isn't strictly | ||
57 | required to use the techniques below. The indices can be increased by more | ||
58 | than 1 if multiple items or variable-sized items are to be included in the | ||
59 | buffer, provided that neither index overtakes the other. The implementer must | ||
60 | be careful, however, as a region more than one unit in size may wrap the end of | ||
61 | the buffer and be broken into two segments. | ||
62 | |||
63 | |||
64 | ============================ | ||
65 | MEASURING POWER-OF-2 BUFFERS | ||
66 | ============================ | ||
67 | |||
68 | Calculation of the occupancy or the remaining capacity of an arbitrarily sized | ||
69 | circular buffer would normally be a slow operation, requiring the use of a | ||
70 | modulus (divide) instruction. However, if the buffer is of a power-of-2 size, | ||
71 | then a much quicker bitwise-AND instruction can be used instead. | ||
72 | |||
73 | Linux provides a set of macros for handling power-of-2 circular buffers. These | ||
74 | can be made use of by: | ||
75 | |||
76 | #include <linux/circ_buf.h> | ||
77 | |||
78 | The macros are: | ||
79 | |||
80 | (*) Measure the remaining capacity of a buffer: | ||
81 | |||
82 | CIRC_SPACE(head_index, tail_index, buffer_size); | ||
83 | |||
84 | This returns the amount of space left in the buffer[1] into which items | ||
85 | can be inserted. | ||
86 | |||
87 | |||
88 | (*) Measure the maximum consecutive immediate space in a buffer: | ||
89 | |||
90 | CIRC_SPACE_TO_END(head_index, tail_index, buffer_size); | ||
91 | |||
92 | This returns the amount of consecutive space left in the buffer[1] into | ||
93 | which items can be immediately inserted without having to wrap back to the | ||
94 | beginning of the buffer. | ||
95 | |||
96 | |||
97 | (*) Measure the occupancy of a buffer: | ||
98 | |||
99 | CIRC_CNT(head_index, tail_index, buffer_size); | ||
100 | |||
101 | This returns the number of items currently occupying a buffer[2]. | ||
102 | |||
103 | |||
104 | (*) Measure the non-wrapping occupancy of a buffer: | ||
105 | |||
106 | CIRC_CNT_TO_END(head_index, tail_index, buffer_size); | ||
107 | |||
108 | This returns the number of consecutive items[2] that can be extracted from | ||
109 | the buffer without having to wrap back to the beginning of the buffer. | ||
110 | |||
111 | |||
112 | Each of these macros will nominally return a value between 0 and buffer_size-1, | ||
113 | however: | ||
114 | |||
115 | [1] CIRC_SPACE*() are intended to be used in the producer. To the producer | ||
116 | they will return a lower bound as the producer controls the head index, | ||
117 | but the consumer may still be depleting the buffer on another CPU and | ||
118 | moving the tail index. | ||
119 | |||
120 | To the consumer it will show an upper bound as the producer may be busy | ||
121 | depleting the space. | ||
122 | |||
123 | [2] CIRC_CNT*() are intended to be used in the consumer. To the consumer they | ||
124 | will return a lower bound as the consumer controls the tail index, but the | ||
125 | producer may still be filling the buffer on another CPU and moving the | ||
126 | head index. | ||
127 | |||
128 | To the producer it will show an upper bound as the consumer may be busy | ||
129 | emptying the buffer. | ||
130 | |||
131 | [3] To a third party, the order in which the writes to the indices by the | ||
132 | producer and consumer become visible cannot be guaranteed as they are | ||
133 | independent and may be made on different CPUs - so the result in such a | ||
134 | situation will merely be a guess, and may even be negative. | ||
135 | |||
136 | |||
137 | =========================================== | ||
138 | USING MEMORY BARRIERS WITH CIRCULAR BUFFERS | ||
139 | =========================================== | ||
140 | |||
141 | By using memory barriers in conjunction with circular buffers, you can avoid | ||
142 | the need to: | ||
143 | |||
144 | (1) use a single lock to govern access to both ends of the buffer, thus | ||
145 | allowing the buffer to be filled and emptied at the same time; and | ||
146 | |||
147 | (2) use atomic counter operations. | ||
148 | |||
149 | There are two sides to this: the producer that fills the buffer, and the | ||
150 | consumer that empties it. Only one thing should be filling a buffer at any one | ||
151 | time, and only one thing should be emptying a buffer at any one time, but the | ||
152 | two sides can operate simultaneously. | ||
153 | |||
154 | |||
155 | THE PRODUCER | ||
156 | ------------ | ||
157 | |||
158 | The producer will look something like this: | ||
159 | |||
160 | spin_lock(&producer_lock); | ||
161 | |||
162 | unsigned long head = buffer->head; | ||
163 | unsigned long tail = ACCESS_ONCE(buffer->tail); | ||
164 | |||
165 | if (CIRC_SPACE(head, tail, buffer->size) >= 1) { | ||
166 | /* insert one item into the buffer */ | ||
167 | struct item *item = buffer[head]; | ||
168 | |||
169 | produce_item(item); | ||
170 | |||
171 | smp_wmb(); /* commit the item before incrementing the head */ | ||
172 | |||
173 | buffer->head = (head + 1) & (buffer->size - 1); | ||
174 | |||
175 | /* wake_up() will make sure that the head is committed before | ||
176 | * waking anyone up */ | ||
177 | wake_up(consumer); | ||
178 | } | ||
179 | |||
180 | spin_unlock(&producer_lock); | ||
181 | |||
182 | This will instruct the CPU that the contents of the new item must be written | ||
183 | before the head index makes it available to the consumer and then instructs the | ||
184 | CPU that the revised head index must be written before the consumer is woken. | ||
185 | |||
186 | Note that wake_up() doesn't have to be the exact mechanism used, but whatever | ||
187 | is used must guarantee a (write) memory barrier between the update of the head | ||
188 | index and the change of state of the consumer, if a change of state occurs. | ||
189 | |||
190 | |||
191 | THE CONSUMER | ||
192 | ------------ | ||
193 | |||
194 | The consumer will look something like this: | ||
195 | |||
196 | spin_lock(&consumer_lock); | ||
197 | |||
198 | unsigned long head = ACCESS_ONCE(buffer->head); | ||
199 | unsigned long tail = buffer->tail; | ||
200 | |||
201 | if (CIRC_CNT(head, tail, buffer->size) >= 1) { | ||
202 | /* read index before reading contents at that index */ | ||
203 | smp_read_barrier_depends(); | ||
204 | |||
205 | /* extract one item from the buffer */ | ||
206 | struct item *item = buffer[tail]; | ||
207 | |||
208 | consume_item(item); | ||
209 | |||
210 | smp_mb(); /* finish reading descriptor before incrementing tail */ | ||
211 | |||
212 | buffer->tail = (tail + 1) & (buffer->size - 1); | ||
213 | } | ||
214 | |||
215 | spin_unlock(&consumer_lock); | ||
216 | |||
217 | This will instruct the CPU to make sure the index is up to date before reading | ||
218 | the new item, and then it shall make sure the CPU has finished reading the item | ||
219 | before it writes the new tail pointer, which will erase the item. | ||
220 | |||
221 | |||
222 | Note the use of ACCESS_ONCE() in both algorithms to read the opposition index. | ||
223 | This prevents the compiler from discarding and reloading its cached value - | ||
224 | which some compilers will do across smp_read_barrier_depends(). This isn't | ||
225 | strictly needed if you can be sure that the opposition index will _only_ be | ||
226 | used the once. | ||
227 | |||
228 | |||
229 | =============== | ||
230 | FURTHER READING | ||
231 | =============== | ||
232 | |||
233 | See also Documentation/memory-barriers.txt for a description of Linux's memory | ||
234 | barrier facilities. | ||
diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c index b07add3467f1..7764594778d4 100644 --- a/Documentation/connector/cn_test.c +++ b/Documentation/connector/cn_test.c | |||
@@ -25,6 +25,7 @@ | |||
25 | #include <linux/module.h> | 25 | #include <linux/module.h> |
26 | #include <linux/moduleparam.h> | 26 | #include <linux/moduleparam.h> |
27 | #include <linux/skbuff.h> | 27 | #include <linux/skbuff.h> |
28 | #include <linux/slab.h> | ||
28 | #include <linux/timer.h> | 29 | #include <linux/timer.h> |
29 | 30 | ||
30 | #include <linux/connector.h> | 31 | #include <linux/connector.h> |
diff --git a/Documentation/fb/imacfb.txt b/Documentation/fb/efifb.txt index 316ec9bb7deb..a59916c29b33 100644 --- a/Documentation/fb/imacfb.txt +++ b/Documentation/fb/efifb.txt | |||
@@ -1,9 +1,9 @@ | |||
1 | 1 | ||
2 | What is imacfb? | 2 | What is efifb? |
3 | =============== | 3 | =============== |
4 | 4 | ||
5 | This is a generic EFI platform driver for Intel based Apple computers. | 5 | This is a generic EFI platform driver for Intel based Apple computers. |
6 | Imacfb is only for EFI booted Intel Macs. | 6 | efifb is only for EFI booted Intel Macs. |
7 | 7 | ||
8 | Supported Hardware | 8 | Supported Hardware |
9 | ================== | 9 | ================== |
@@ -16,16 +16,16 @@ MacMini | |||
16 | How to use it? | 16 | How to use it? |
17 | ============== | 17 | ============== |
18 | 18 | ||
19 | Imacfb does not have any kind of autodetection of your machine. | 19 | efifb does not have any kind of autodetection of your machine. |
20 | You have to add the following kernel parameters in your elilo.conf: | 20 | You have to add the following kernel parameters in your elilo.conf: |
21 | Macbook : | 21 | Macbook : |
22 | video=imacfb:macbook | 22 | video=efifb:macbook |
23 | MacMini : | 23 | MacMini : |
24 | video=imacfb:mini | 24 | video=efifb:mini |
25 | Macbook Pro 15", iMac 17" : | 25 | Macbook Pro 15", iMac 17" : |
26 | video=imacfb:i17 | 26 | video=efifb:i17 |
27 | Macbook Pro 17", iMac 20" : | 27 | Macbook Pro 17", iMac 20" : |
28 | video=imacfb:i20 | 28 | video=efifb:i20 |
29 | 29 | ||
30 | -- | 30 | -- |
31 | Edgar Hucek <gimli@dark-green.com> | 31 | Edgar Hucek <gimli@dark-green.com> |
diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index 3bae418c6ad3..4303614b5add 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX | |||
@@ -16,6 +16,8 @@ befs.txt | |||
16 | - information about the BeOS filesystem for Linux. | 16 | - information about the BeOS filesystem for Linux. |
17 | bfs.txt | 17 | bfs.txt |
18 | - info for the SCO UnixWare Boot Filesystem (BFS). | 18 | - info for the SCO UnixWare Boot Filesystem (BFS). |
19 | ceph.txt | ||
20 | - info for the Ceph Distributed File System | ||
19 | cifs.txt | 21 | cifs.txt |
20 | - description of the CIFS filesystem. | 22 | - description of the CIFS filesystem. |
21 | coda.txt | 23 | coda.txt |
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index 57e0b80a5274..c0236e753bc8 100644 --- a/Documentation/filesystems/9p.txt +++ b/Documentation/filesystems/9p.txt | |||
@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9) | |||
37 | 37 | ||
38 | mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER | 38 | mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER |
39 | 39 | ||
40 | For server running on QEMU host with virtio transport: | ||
41 | |||
42 | mount -t 9p -o trans=virtio <mount_tag> /mnt/9 | ||
43 | |||
44 | where mount_tag is the tag associated by the server to each of the exported | ||
45 | mount points. Each 9P export is seen by the client as a virtio device with an | ||
46 | associated "mount_tag" property. Available mount tags can be | ||
47 | seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files. | ||
48 | |||
40 | OPTIONS | 49 | OPTIONS |
41 | ======= | 50 | ======= |
42 | 51 | ||
@@ -47,7 +56,7 @@ OPTIONS | |||
47 | fd - used passed file descriptors for connection | 56 | fd - used passed file descriptors for connection |
48 | (see rfdno and wfdno) | 57 | (see rfdno and wfdno) |
49 | virtio - connect to the next virtio channel available | 58 | virtio - connect to the next virtio channel available |
50 | (from lguest or KVM with trans_virtio module) | 59 | (from QEMU with trans_virtio module) |
51 | rdma - connect to a specified RDMA channel | 60 | rdma - connect to a specified RDMA channel |
52 | 61 | ||
53 | uname=name user name to attempt mount as on the remote server. The | 62 | uname=name user name to attempt mount as on the remote server. The |
@@ -85,7 +94,12 @@ OPTIONS | |||
85 | 94 | ||
86 | port=n port to connect to on the remote server | 95 | port=n port to connect to on the remote server |
87 | 96 | ||
88 | noextend force legacy mode (no 9p2000.u semantics) | 97 | noextend force legacy mode (no 9p2000.u or 9p2000.L semantics) |
98 | |||
99 | version=name Select 9P protocol version. Valid options are: | ||
100 | 9p2000 - Legacy mode (same as noextend) | ||
101 | 9p2000.u - Use 9P2000.u protocol | ||
102 | 9p2000.L - Use 9P2000.L protocol | ||
89 | 103 | ||
90 | dfltuid attempt to mount as a particular uid | 104 | dfltuid attempt to mount as a particular uid |
91 | 105 | ||
diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt index 6e03917316bd..0660c9f5deef 100644 --- a/Documentation/filesystems/ceph.txt +++ b/Documentation/filesystems/ceph.txt | |||
@@ -8,7 +8,7 @@ Basic features include: | |||
8 | 8 | ||
9 | * POSIX semantics | 9 | * POSIX semantics |
10 | * Seamless scaling from 1 to many thousands of nodes | 10 | * Seamless scaling from 1 to many thousands of nodes |
11 | * High availability and reliability. No single points of failure. | 11 | * High availability and reliability. No single point of failure. |
12 | * N-way replication of data across storage nodes | 12 | * N-way replication of data across storage nodes |
13 | * Fast recovery from node failures | 13 | * Fast recovery from node failures |
14 | * Automatic rebalancing of data on node addition/removal | 14 | * Automatic rebalancing of data on node addition/removal |
@@ -94,7 +94,7 @@ Mount Options | |||
94 | 94 | ||
95 | wsize=X | 95 | wsize=X |
96 | Specify the maximum write size in bytes. By default there is no | 96 | Specify the maximum write size in bytes. By default there is no |
97 | maximu. Ceph will normally size writes based on the file stripe | 97 | maximum. Ceph will normally size writes based on the file stripe |
98 | size. | 98 | size. |
99 | 99 | ||
100 | rsize=X | 100 | rsize=X |
@@ -115,7 +115,7 @@ Mount Options | |||
115 | number of entries in that directory. | 115 | number of entries in that directory. |
116 | 116 | ||
117 | nocrc | 117 | nocrc |
118 | Disable CRC32C calculation for data writes. If set, the OSD | 118 | Disable CRC32C calculation for data writes. If set, the storage node |
119 | must rely on TCP's error correction to detect data corruption | 119 | must rely on TCP's error correction to detect data corruption |
120 | in the data payload. | 120 | in the data payload. |
121 | 121 | ||
@@ -133,7 +133,8 @@ For more information on Ceph, see the home page at | |||
133 | http://ceph.newdream.net/ | 133 | http://ceph.newdream.net/ |
134 | 134 | ||
135 | The Linux kernel client source tree is available at | 135 | The Linux kernel client source tree is available at |
136 | git://ceph.newdream.net/linux-ceph-client.git | 136 | git://ceph.newdream.net/git/ceph-client.git |
137 | git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git | ||
137 | 138 | ||
138 | and the source for the full system is at | 139 | and the source for the full system is at |
139 | git://ceph.newdream.net/ceph.git | 140 | git://ceph.newdream.net/git/ceph.git |
diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt index 3015da0c6b2a..fe09a2cb1858 100644 --- a/Documentation/filesystems/tmpfs.txt +++ b/Documentation/filesystems/tmpfs.txt | |||
@@ -82,11 +82,13 @@ tmpfs has a mount option to set the NUMA memory allocation policy for | |||
82 | all files in that instance (if CONFIG_NUMA is enabled) - which can be | 82 | all files in that instance (if CONFIG_NUMA is enabled) - which can be |
83 | adjusted on the fly via 'mount -o remount ...' | 83 | adjusted on the fly via 'mount -o remount ...' |
84 | 84 | ||
85 | mpol=default prefers to allocate memory from the local node | 85 | mpol=default use the process allocation policy |
86 | (see set_mempolicy(2)) | ||
86 | mpol=prefer:Node prefers to allocate memory from the given Node | 87 | mpol=prefer:Node prefers to allocate memory from the given Node |
87 | mpol=bind:NodeList allocates memory only from nodes in NodeList | 88 | mpol=bind:NodeList allocates memory only from nodes in NodeList |
88 | mpol=interleave prefers to allocate from each node in turn | 89 | mpol=interleave prefers to allocate from each node in turn |
89 | mpol=interleave:NodeList allocates from each node of NodeList in turn | 90 | mpol=interleave:NodeList allocates from each node of NodeList in turn |
91 | mpol=local prefers to allocate memory from the local node | ||
90 | 92 | ||
91 | NodeList format is a comma-separated list of decimal numbers and ranges, | 93 | NodeList format is a comma-separated list of decimal numbers and ranges, |
92 | a range being two hyphen-separated decimal numbers, the smallest and | 94 | a range being two hyphen-separated decimal numbers, the smallest and |
@@ -134,3 +136,5 @@ Author: | |||
134 | Christoph Rohland <cr@sap.com>, 1.12.01 | 136 | Christoph Rohland <cr@sap.com>, 1.12.01 |
135 | Updated: | 137 | Updated: |
136 | Hugh Dickins, 4 June 2007 | 138 | Hugh Dickins, 4 June 2007 |
139 | Updated: | ||
140 | KOSAKI Motohiro, 16 Mar 2010 | ||
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 7f5809eddee6..631ad2f1b229 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt | |||
@@ -3,6 +3,7 @@ | |||
3 | ============================ | 3 | ============================ |
4 | 4 | ||
5 | By: David Howells <dhowells@redhat.com> | 5 | By: David Howells <dhowells@redhat.com> |
6 | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | ||
6 | 7 | ||
7 | Contents: | 8 | Contents: |
8 | 9 | ||
@@ -60,6 +61,10 @@ Contents: | |||
60 | 61 | ||
61 | - And then there's the Alpha. | 62 | - And then there's the Alpha. |
62 | 63 | ||
64 | (*) Example uses. | ||
65 | |||
66 | - Circular buffers. | ||
67 | |||
63 | (*) References. | 68 | (*) References. |
64 | 69 | ||
65 | 70 | ||
@@ -2226,6 +2231,21 @@ The Alpha defines the Linux kernel's memory barrier model. | |||
2226 | See the subsection on "Cache Coherency" above. | 2231 | See the subsection on "Cache Coherency" above. |
2227 | 2232 | ||
2228 | 2233 | ||
2234 | ============ | ||
2235 | EXAMPLE USES | ||
2236 | ============ | ||
2237 | |||
2238 | CIRCULAR BUFFERS | ||
2239 | ---------------- | ||
2240 | |||
2241 | Memory barriers can be used to implement circular buffering without the need | ||
2242 | of a lock to serialise the producer with the consumer. See: | ||
2243 | |||
2244 | Documentation/circular-buffers.txt | ||
2245 | |||
2246 | for details. | ||
2247 | |||
2248 | |||
2229 | ========== | 2249 | ========== |
2230 | REFERENCES | 2250 | REFERENCES |
2231 | ========== | 2251 | ========== |
diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 0e58b4539176..e8c8f4f06c67 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt | |||
@@ -41,11 +41,12 @@ SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in | |||
41 | SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. | 41 | SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. |
42 | SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the | 42 | SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the |
43 | following control message: | 43 | following control message: |
44 | struct scm_timestamping { | 44 | |
45 | struct timespec systime; | 45 | struct scm_timestamping { |
46 | struct timespec hwtimetrans; | 46 | struct timespec systime; |
47 | struct timespec hwtimeraw; | 47 | struct timespec hwtimetrans; |
48 | }; | 48 | struct timespec hwtimeraw; |
49 | }; | ||
49 | 50 | ||
50 | recvmsg() can be used to get this control message for regular incoming | 51 | recvmsg() can be used to get this control message for regular incoming |
51 | packets. For send time stamps the outgoing packet is looped back to | 52 | packets. For send time stamps the outgoing packet is looped back to |
@@ -87,12 +88,13 @@ by the network device and will be empty without that support. | |||
87 | SIOCSHWTSTAMP: | 88 | SIOCSHWTSTAMP: |
88 | 89 | ||
89 | Hardware time stamping must also be initialized for each device driver | 90 | Hardware time stamping must also be initialized for each device driver |
90 | that is expected to do hardware time stamping. The parameter is: | 91 | that is expected to do hardware time stamping. The parameter is defined in |
92 | /include/linux/net_tstamp.h as: | ||
91 | 93 | ||
92 | struct hwtstamp_config { | 94 | struct hwtstamp_config { |
93 | int flags; /* no flags defined right now, must be zero */ | 95 | int flags; /* no flags defined right now, must be zero */ |
94 | int tx_type; /* HWTSTAMP_TX_* */ | 96 | int tx_type; /* HWTSTAMP_TX_* */ |
95 | int rx_filter; /* HWTSTAMP_FILTER_* */ | 97 | int rx_filter; /* HWTSTAMP_FILTER_* */ |
96 | }; | 98 | }; |
97 | 99 | ||
98 | Desired behavior is passed into the kernel and to a specific device by | 100 | Desired behavior is passed into the kernel and to a specific device by |
@@ -139,42 +141,56 @@ enum { | |||
139 | /* time stamp any incoming packet */ | 141 | /* time stamp any incoming packet */ |
140 | HWTSTAMP_FILTER_ALL, | 142 | HWTSTAMP_FILTER_ALL, |
141 | 143 | ||
142 | /* return value: time stamp all packets requested plus some others */ | 144 | /* return value: time stamp all packets requested plus some others */ |
143 | HWTSTAMP_FILTER_SOME, | 145 | HWTSTAMP_FILTER_SOME, |
144 | 146 | ||
145 | /* PTP v1, UDP, any kind of event packet */ | 147 | /* PTP v1, UDP, any kind of event packet */ |
146 | HWTSTAMP_FILTER_PTP_V1_L4_EVENT, | 148 | HWTSTAMP_FILTER_PTP_V1_L4_EVENT, |
147 | 149 | ||
148 | ... | 150 | /* for the complete list of values, please check |
151 | * the include file /include/linux/net_tstamp.h | ||
152 | */ | ||
149 | }; | 153 | }; |
150 | 154 | ||
151 | 155 | ||
152 | DEVICE IMPLEMENTATION | 156 | DEVICE IMPLEMENTATION |
153 | 157 | ||
154 | A driver which supports hardware time stamping must support the | 158 | A driver which supports hardware time stamping must support the |
155 | SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored | 159 | SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with |
156 | in the skb with skb_hwtstamp_set(). | 160 | the actual values as described in the section on SIOCSHWTSTAMP. |
161 | |||
162 | Time stamps for received packets must be stored in the skb. To get a pointer | ||
163 | to the shared time stamp structure of the skb call skb_hwtstamps(). Then | ||
164 | set the time stamps in the structure: | ||
165 | |||
166 | struct skb_shared_hwtstamps { | ||
167 | /* hardware time stamp transformed into duration | ||
168 | * since arbitrary point in time | ||
169 | */ | ||
170 | ktime_t hwtstamp; | ||
171 | ktime_t syststamp; /* hwtstamp transformed to system time base */ | ||
172 | }; | ||
157 | 173 | ||
158 | Time stamps for outgoing packets are to be generated as follows: | 174 | Time stamps for outgoing packets are to be generated as follows: |
159 | - In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware() | 175 | - In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero. |
160 | returns non-zero. If yes, then the driver is expected | 176 | If yes, then the driver is expected to do hardware time stamping. |
161 | to do hardware time stamping. | ||
162 | - If this is possible for the skb and requested, then declare | 177 | - If this is possible for the skb and requested, then declare |
163 | that the driver is doing the time stamping by calling | 178 | that the driver is doing the time stamping by setting the field |
164 | skb_hwtstamp_tx_in_progress(). A driver not supporting | 179 | skb_tx(skb)->in_progress non-zero. You might want to keep a pointer |
165 | hardware time stamping doesn't do that. A driver must never | 180 | to the associated skb for the next step and not free the skb. A driver |
166 | touch sk_buff::tstamp! It is used to store how time stamping | 181 | not supporting hardware time stamping doesn't do that. A driver must |
167 | for an outgoing packets is to be done. | 182 | never touch sk_buff::tstamp! It is used to store software generated |
183 | time stamps by the network subsystem. | ||
168 | - As soon as the driver has sent the packet and/or obtained a | 184 | - As soon as the driver has sent the packet and/or obtained a |
169 | hardware time stamp for it, it passes the time stamp back by | 185 | hardware time stamp for it, it passes the time stamp back by |
170 | calling skb_hwtstamp_tx() with the original skb, the raw | 186 | calling skb_hwtstamp_tx() with the original skb, the raw |
171 | hardware time stamp and a handle to the device (necessary | 187 | hardware time stamp. skb_hwtstamp_tx() clones the original skb and |
172 | to convert the hardware time stamp to system time). If obtaining | 188 | adds the timestamps, therefore the original skb has to be freed now. |
173 | the hardware time stamp somehow fails, then the driver should | 189 | If obtaining the hardware time stamp somehow fails, then the driver |
174 | not fall back to software time stamping. The rationale is that | 190 | should not fall back to software time stamping. The rationale is that |
175 | this would occur at a later time in the processing pipeline | 191 | this would occur at a later time in the processing pipeline than other |
176 | than other software time stamping and therefore could lead | 192 | software time stamping and therefore could lead to unexpected deltas |
177 | to unexpected deltas between time stamps. | 193 | between time stamps. |
178 | - If the driver did not call skb_hwtstamp_tx_in_progress(), then | 194 | - If the driver did not call set skb_tx(skb)->in_progress, then |
179 | dev_hard_start_xmit() checks whether software time stamping | 195 | dev_hard_start_xmit() checks whether software time stamping |
180 | is wanted as fallback and potentially generates the time stamp. | 196 | is wanted as fallback and potentially generates the time stamp. |
diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt index 6e37be1eeb2d..4f8930263dd9 100644 --- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt +++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt | |||
@@ -21,6 +21,15 @@ Required properties: | |||
21 | - fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the | 21 | - fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the |
22 | threads. | 22 | threads. |
23 | 23 | ||
24 | Optional properties: | ||
25 | - fsl,firmware-phandle: | ||
26 | Usage: required only if there is no fsl,qe-firmware child node | ||
27 | Value type: <phandle> | ||
28 | Definition: Points to a firmware node (see "QE Firmware Node" below) | ||
29 | that contains the firmware that should be uploaded for this QE. | ||
30 | The compatible property for the firmware node should say, | ||
31 | "fsl,qe-firmware". | ||
32 | |||
24 | Recommended properties | 33 | Recommended properties |
25 | - brg-frequency : the internal clock source frequency for baud-rate | 34 | - brg-frequency : the internal clock source frequency for baud-rate |
26 | generators in Hz. | 35 | generators in Hz. |
@@ -59,3 +68,48 @@ Example: | |||
59 | reg = <0 c000>; | 68 | reg = <0 c000>; |
60 | }; | 69 | }; |
61 | }; | 70 | }; |
71 | |||
72 | * QE Firmware Node | ||
73 | |||
74 | This node defines a firmware binary that is embedded in the device tree, for | ||
75 | the purpose of passing the firmware from bootloader to the kernel, or from | ||
76 | the hypervisor to the guest. | ||
77 | |||
78 | The firmware node itself contains the firmware binary contents, a compatible | ||
79 | property, and any firmware-specific properties. The node should be placed | ||
80 | inside a QE node that needs it. Doing so eliminates the need for a | ||
81 | fsl,firmware-phandle property. Other QE nodes that need the same firmware | ||
82 | should define an fsl,firmware-phandle property that points to the firmware node | ||
83 | in the first QE node. | ||
84 | |||
85 | The fsl,firmware property can be specified in the DTS (possibly using incbin) | ||
86 | or can be inserted by the boot loader at boot time. | ||
87 | |||
88 | Required properties: | ||
89 | - compatible | ||
90 | Usage: required | ||
91 | Value type: <string> | ||
92 | Definition: A standard property. Specify a string that indicates what | ||
93 | kind of firmware it is. For QE, this should be "fsl,qe-firmware". | ||
94 | |||
95 | - fsl,firmware | ||
96 | Usage: required | ||
97 | Value type: <prop-encoded-array>, encoded as an array of bytes | ||
98 | Definition: A standard property. This property contains the firmware | ||
99 | binary "blob". | ||
100 | |||
101 | Example: | ||
102 | qe1@e0080000 { | ||
103 | compatible = "fsl,qe"; | ||
104 | qe_firmware:qe-firmware { | ||
105 | compatible = "fsl,qe-firmware"; | ||
106 | fsl,firmware = [0x70 0xcd 0x00 0x00 0x01 0x46 0x45 ...]; | ||
107 | }; | ||
108 | ... | ||
109 | }; | ||
110 | |||
111 | qe2@e0090000 { | ||
112 | compatible = "fsl,qe"; | ||
113 | fsl,firmware-phandle = <&qe_firmware>; | ||
114 | ... | ||
115 | }; | ||
diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt index f4dd3bf99d12..98d14cb8a85d 100644 --- a/Documentation/sound/alsa/HD-Audio.txt +++ b/Documentation/sound/alsa/HD-Audio.txt | |||
@@ -119,10 +119,18 @@ the codec slots 0 and 1 no matter what the hardware reports. | |||
119 | 119 | ||
120 | Interrupt Handling | 120 | Interrupt Handling |
121 | ~~~~~~~~~~~~~~~~~~ | 121 | ~~~~~~~~~~~~~~~~~~ |
122 | In rare but some cases, the interrupt isn't properly handled as | 122 | HD-audio driver uses MSI as default (if available) since 2.6.33 |
123 | default. You would notice this by the DMA transfer error reported by | 123 | kernel as MSI works better on some machines, and in general, it's |
124 | ALSA PCM core, for example. Using MSI might help in such a case. | 124 | better for performance. However, Nvidia controllers showed bad |
125 | Pass `enable_msi=1` option for enabling MSI. | 125 | regressions with MSI (especially in a combination with AMD chipset), |
126 | thus we disabled MSI for them. | ||
127 | |||
128 | There seem also still other devices that don't work with MSI. If you | ||
129 | see a regression wrt the sound quality (stuttering, etc) or a lock-up | ||
130 | in the recent kernel, try to pass `enable_msi=0` option to disable | ||
131 | MSI. If it works, you can add the known bad device to the blacklist | ||
132 | defined in hda_intel.c. In such a case, please report and give the | ||
133 | patch back to the upstream developer. | ||
126 | 134 | ||
127 | 135 | ||
128 | HD-AUDIO CODEC | 136 | HD-AUDIO CODEC |
diff --git a/Documentation/volatile-considered-harmful.txt b/Documentation/volatile-considered-harmful.txt index 991c26a6ef64..db0cb228d64a 100644 --- a/Documentation/volatile-considered-harmful.txt +++ b/Documentation/volatile-considered-harmful.txt | |||
@@ -63,9 +63,9 @@ way to perform a busy wait is: | |||
63 | cpu_relax(); | 63 | cpu_relax(); |
64 | 64 | ||
65 | The cpu_relax() call can lower CPU power consumption or yield to a | 65 | The cpu_relax() call can lower CPU power consumption or yield to a |
66 | hyperthreaded twin processor; it also happens to serve as a memory barrier, | 66 | hyperthreaded twin processor; it also happens to serve as a compiler |
67 | so, once again, volatile is unnecessary. Of course, busy-waiting is | 67 | barrier, so, once again, volatile is unnecessary. Of course, busy- |
68 | generally an anti-social act to begin with. | 68 | waiting is generally an anti-social act to begin with. |
69 | 69 | ||
70 | There are still a few rare situations where volatile makes sense in the | 70 | There are still a few rare situations where volatile makes sense in the |
71 | kernel: | 71 | kernel: |
diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c index 4cf72f3fa8e9..ba45803a2216 100644 --- a/Documentation/watchdog/src/watchdog-simple.c +++ b/Documentation/watchdog/src/watchdog-simple.c | |||
@@ -17,9 +17,6 @@ int main(void) | |||
17 | ret = -1; | 17 | ret = -1; |
18 | break; | 18 | break; |
19 | } | 19 | } |
20 | ret = fsync(fd); | ||
21 | if (ret) | ||
22 | break; | ||
23 | sleep(10); | 20 | sleep(10); |
24 | } | 21 | } |
25 | close(fd); | 22 | close(fd); |
diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c index a750532ffcf8..63fdc34ceb98 100644 --- a/Documentation/watchdog/src/watchdog-test.c +++ b/Documentation/watchdog/src/watchdog-test.c | |||
@@ -31,6 +31,8 @@ static void keep_alive(void) | |||
31 | */ | 31 | */ |
32 | int main(int argc, char *argv[]) | 32 | int main(int argc, char *argv[]) |
33 | { | 33 | { |
34 | int flags; | ||
35 | |||
34 | fd = open("/dev/watchdog", O_WRONLY); | 36 | fd = open("/dev/watchdog", O_WRONLY); |
35 | 37 | ||
36 | if (fd == -1) { | 38 | if (fd == -1) { |
@@ -41,12 +43,14 @@ int main(int argc, char *argv[]) | |||
41 | 43 | ||
42 | if (argc > 1) { | 44 | if (argc > 1) { |
43 | if (!strncasecmp(argv[1], "-d", 2)) { | 45 | if (!strncasecmp(argv[1], "-d", 2)) { |
44 | ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD); | 46 | flags = WDIOS_DISABLECARD; |
47 | ioctl(fd, WDIOC_SETOPTIONS, &flags); | ||
45 | fprintf(stderr, "Watchdog card disabled.\n"); | 48 | fprintf(stderr, "Watchdog card disabled.\n"); |
46 | fflush(stderr); | 49 | fflush(stderr); |
47 | exit(0); | 50 | exit(0); |
48 | } else if (!strncasecmp(argv[1], "-e", 2)) { | 51 | } else if (!strncasecmp(argv[1], "-e", 2)) { |
49 | ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD); | 52 | flags = WDIOS_ENABLECARD; |
53 | ioctl(fd, WDIOC_SETOPTIONS, &flags); | ||
50 | fprintf(stderr, "Watchdog card enabled.\n"); | 54 | fprintf(stderr, "Watchdog card enabled.\n"); |
51 | fflush(stderr); | 55 | fflush(stderr); |
52 | exit(0); | 56 | exit(0); |
diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt index 4cc4ba9d7150..eb7132ed8bbc 100644 --- a/Documentation/watchdog/watchdog-api.txt +++ b/Documentation/watchdog/watchdog-api.txt | |||
@@ -222,11 +222,10 @@ returned value is the temperature in degrees fahrenheit. | |||
222 | ioctl(fd, WDIOC_GETTEMP, &temperature); | 222 | ioctl(fd, WDIOC_GETTEMP, &temperature); |
223 | 223 | ||
224 | Finally the SETOPTIONS ioctl can be used to control some aspects of | 224 | Finally the SETOPTIONS ioctl can be used to control some aspects of |
225 | the cards operation; right now the pcwd driver is the only one | 225 | the cards operation. |
226 | supporting this ioctl. | ||
227 | 226 | ||
228 | int options = 0; | 227 | int options = 0; |
229 | ioctl(fd, WDIOC_SETOPTIONS, options); | 228 | ioctl(fd, WDIOC_SETOPTIONS, &options); |
230 | 229 | ||
231 | The following options are available: | 230 | The following options are available: |
232 | 231 | ||