diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 2 | ||||
-rw-r--r-- | Documentation/DMA-API-HOWTO.txt (renamed from Documentation/PCI/PCI-DMA-mapping.txt) | 0 | ||||
-rw-r--r-- | Documentation/cgroups/memory.txt | 2 | ||||
-rw-r--r-- | Documentation/circular-buffers.txt | 234 | ||||
-rw-r--r-- | Documentation/connector/cn_test.c | 1 | ||||
-rw-r--r-- | Documentation/filesystems/00-INDEX | 2 | ||||
-rw-r--r-- | Documentation/filesystems/9p.txt | 18 | ||||
-rw-r--r-- | Documentation/filesystems/ceph.txt | 140 | ||||
-rw-r--r-- | Documentation/filesystems/tmpfs.txt | 6 | ||||
-rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 1 | ||||
-rw-r--r-- | Documentation/kobject.txt | 60 | ||||
-rw-r--r-- | Documentation/memory-barriers.txt | 20 | ||||
-rw-r--r-- | Documentation/networking/stmmac.txt | 143 | ||||
-rw-r--r-- | Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt | 54 | ||||
-rw-r--r-- | Documentation/volatile-considered-harmful.txt | 6 |
15 files changed, 661 insertions, 28 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index a986e9bbba3d..bcebb9eaedce 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb | |||
@@ -160,7 +160,7 @@ Description: | |||
160 | match the driver to the device. For example: | 160 | match the driver to the device. For example: |
161 | # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id | 161 | # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id |
162 | 162 | ||
163 | What: /sys/bus/usb/device/.../avoid_reset | 163 | What: /sys/bus/usb/device/.../avoid_reset_quirk |
164 | Date: December 2009 | 164 | Date: December 2009 |
165 | Contact: Oliver Neukum <oliver@neukum.org> | 165 | Contact: Oliver Neukum <oliver@neukum.org> |
166 | Description: | 166 | Description: |
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/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/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 new file mode 100644 index 000000000000..0660c9f5deef --- /dev/null +++ b/Documentation/filesystems/ceph.txt | |||
@@ -0,0 +1,140 @@ | |||
1 | Ceph Distributed File System | ||
2 | ============================ | ||
3 | |||
4 | Ceph is a distributed network file system designed to provide good | ||
5 | performance, reliability, and scalability. | ||
6 | |||
7 | Basic features include: | ||
8 | |||
9 | * POSIX semantics | ||
10 | * Seamless scaling from 1 to many thousands of nodes | ||
11 | * High availability and reliability. No single point of failure. | ||
12 | * N-way replication of data across storage nodes | ||
13 | * Fast recovery from node failures | ||
14 | * Automatic rebalancing of data on node addition/removal | ||
15 | * Easy deployment: most FS components are userspace daemons | ||
16 | |||
17 | Also, | ||
18 | * Flexible snapshots (on any directory) | ||
19 | * Recursive accounting (nested files, directories, bytes) | ||
20 | |||
21 | In contrast to cluster filesystems like GFS, OCFS2, and GPFS that rely | ||
22 | on symmetric access by all clients to shared block devices, Ceph | ||
23 | separates data and metadata management into independent server | ||
24 | clusters, similar to Lustre. Unlike Lustre, however, metadata and | ||
25 | storage nodes run entirely as user space daemons. Storage nodes | ||
26 | utilize btrfs to store data objects, leveraging its advanced features | ||
27 | (checksumming, metadata replication, etc.). File data is striped | ||
28 | across storage nodes in large chunks to distribute workload and | ||
29 | facilitate high throughputs. When storage nodes fail, data is | ||
30 | re-replicated in a distributed fashion by the storage nodes themselves | ||
31 | (with some minimal coordination from a cluster monitor), making the | ||
32 | system extremely efficient and scalable. | ||
33 | |||
34 | Metadata servers effectively form a large, consistent, distributed | ||
35 | in-memory cache above the file namespace that is extremely scalable, | ||
36 | dynamically redistributes metadata in response to workload changes, | ||
37 | and can tolerate arbitrary (well, non-Byzantine) node failures. The | ||
38 | metadata server takes a somewhat unconventional approach to metadata | ||
39 | storage to significantly improve performance for common workloads. In | ||
40 | particular, inodes with only a single link are embedded in | ||
41 | directories, allowing entire directories of dentries and inodes to be | ||
42 | loaded into its cache with a single I/O operation. The contents of | ||
43 | extremely large directories can be fragmented and managed by | ||
44 | independent metadata servers, allowing scalable concurrent access. | ||
45 | |||
46 | The system offers automatic data rebalancing/migration when scaling | ||
47 | from a small cluster of just a few nodes to many hundreds, without | ||
48 | requiring an administrator carve the data set into static volumes or | ||
49 | go through the tedious process of migrating data between servers. | ||
50 | When the file system approaches full, new nodes can be easily added | ||
51 | and things will "just work." | ||
52 | |||
53 | Ceph includes flexible snapshot mechanism that allows a user to create | ||
54 | a snapshot on any subdirectory (and its nested contents) in the | ||
55 | system. Snapshot creation and deletion are as simple as 'mkdir | ||
56 | .snap/foo' and 'rmdir .snap/foo'. | ||
57 | |||
58 | Ceph also provides some recursive accounting on directories for nested | ||
59 | files and bytes. That is, a 'getfattr -d foo' on any directory in the | ||
60 | system will reveal the total number of nested regular files and | ||
61 | subdirectories, and a summation of all nested file sizes. This makes | ||
62 | the identification of large disk space consumers relatively quick, as | ||
63 | no 'du' or similar recursive scan of the file system is required. | ||
64 | |||
65 | |||
66 | Mount Syntax | ||
67 | ============ | ||
68 | |||
69 | The basic mount syntax is: | ||
70 | |||
71 | # mount -t ceph monip[:port][,monip2[:port]...]:/[subdir] mnt | ||
72 | |||
73 | You only need to specify a single monitor, as the client will get the | ||
74 | full list when it connects. (However, if the monitor you specify | ||
75 | happens to be down, the mount won't succeed.) The port can be left | ||
76 | off if the monitor is using the default. So if the monitor is at | ||
77 | 1.2.3.4, | ||
78 | |||
79 | # mount -t ceph 1.2.3.4:/ /mnt/ceph | ||
80 | |||
81 | is sufficient. If /sbin/mount.ceph is installed, a hostname can be | ||
82 | used instead of an IP address. | ||
83 | |||
84 | |||
85 | |||
86 | Mount Options | ||
87 | ============= | ||
88 | |||
89 | ip=A.B.C.D[:N] | ||
90 | Specify the IP and/or port the client should bind to locally. | ||
91 | There is normally not much reason to do this. If the IP is not | ||
92 | specified, the client's IP address is determined by looking at the | ||
93 | address it's connection to the monitor originates from. | ||
94 | |||
95 | wsize=X | ||
96 | Specify the maximum write size in bytes. By default there is no | ||
97 | maximum. Ceph will normally size writes based on the file stripe | ||
98 | size. | ||
99 | |||
100 | rsize=X | ||
101 | Specify the maximum readahead. | ||
102 | |||
103 | mount_timeout=X | ||
104 | Specify the timeout value for mount (in seconds), in the case | ||
105 | of a non-responsive Ceph file system. The default is 30 | ||
106 | seconds. | ||
107 | |||
108 | rbytes | ||
109 | When stat() is called on a directory, set st_size to 'rbytes', | ||
110 | the summation of file sizes over all files nested beneath that | ||
111 | directory. This is the default. | ||
112 | |||
113 | norbytes | ||
114 | When stat() is called on a directory, set st_size to the | ||
115 | number of entries in that directory. | ||
116 | |||
117 | nocrc | ||
118 | Disable CRC32C calculation for data writes. If set, the storage node | ||
119 | must rely on TCP's error correction to detect data corruption | ||
120 | in the data payload. | ||
121 | |||
122 | noasyncreaddir | ||
123 | Disable client's use its local cache to satisfy readdir | ||
124 | requests. (This does not change correctness; the client uses | ||
125 | cached metadata only when a lease or capability ensures it is | ||
126 | valid.) | ||
127 | |||
128 | |||
129 | More Information | ||
130 | ================ | ||
131 | |||
132 | For more information on Ceph, see the home page at | ||
133 | http://ceph.newdream.net/ | ||
134 | |||
135 | The Linux kernel client source tree is available at | ||
136 | git://ceph.newdream.net/git/ceph-client.git | ||
137 | git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git | ||
138 | |||
139 | and the source for the full system is at | ||
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/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 35c9b51d20ea..dd5806f4fcc4 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt | |||
@@ -291,6 +291,7 @@ Code Seq#(hex) Include File Comments | |||
291 | 0x92 00-0F drivers/usb/mon/mon_bin.c | 291 | 0x92 00-0F drivers/usb/mon/mon_bin.c |
292 | 0x93 60-7F linux/auto_fs.h | 292 | 0x93 60-7F linux/auto_fs.h |
293 | 0x94 all fs/btrfs/ioctl.h | 293 | 0x94 all fs/btrfs/ioctl.h |
294 | 0x97 00-7F fs/ceph/ioctl.h Ceph file system | ||
294 | 0x99 00-0F 537-Addinboard driver | 295 | 0x99 00-0F 537-Addinboard driver |
295 | <mailto:buk@buks.ipn.de> | 296 | <mailto:buk@buks.ipn.de> |
296 | 0xA0 all linux/sdp/sdp.h Industrial Device Project | 297 | 0xA0 all linux/sdp/sdp.h Industrial Device Project |
diff --git a/Documentation/kobject.txt b/Documentation/kobject.txt index bdb13817e1e9..3ab2472509cb 100644 --- a/Documentation/kobject.txt +++ b/Documentation/kobject.txt | |||
@@ -59,37 +59,56 @@ nice to have in other objects. The C language does not allow for the | |||
59 | direct expression of inheritance, so other techniques - such as structure | 59 | direct expression of inheritance, so other techniques - such as structure |
60 | embedding - must be used. | 60 | embedding - must be used. |
61 | 61 | ||
62 | So, for example, the UIO code has a structure that defines the memory | 62 | (As an aside, for those familiar with the kernel linked list implementation, |
63 | region associated with a uio device: | 63 | this is analogous as to how "list_head" structs are rarely useful on |
64 | their own, but are invariably found embedded in the larger objects of | ||
65 | interest.) | ||
64 | 66 | ||
65 | struct uio_mem { | 67 | So, for example, the UIO code in drivers/uio/uio.c has a structure that |
68 | defines the memory region associated with a uio device: | ||
69 | |||
70 | struct uio_map { | ||
66 | struct kobject kobj; | 71 | struct kobject kobj; |
67 | unsigned long addr; | 72 | struct uio_mem *mem; |
68 | unsigned long size; | 73 | }; |
69 | int memtype; | ||
70 | void __iomem *internal_addr; | ||
71 | }; | ||
72 | 74 | ||
73 | If you have a struct uio_mem structure, finding its embedded kobject is | 75 | If you have a struct uio_map structure, finding its embedded kobject is |
74 | just a matter of using the kobj member. Code that works with kobjects will | 76 | just a matter of using the kobj member. Code that works with kobjects will |
75 | often have the opposite problem, however: given a struct kobject pointer, | 77 | often have the opposite problem, however: given a struct kobject pointer, |
76 | what is the pointer to the containing structure? You must avoid tricks | 78 | what is the pointer to the containing structure? You must avoid tricks |
77 | (such as assuming that the kobject is at the beginning of the structure) | 79 | (such as assuming that the kobject is at the beginning of the structure) |
78 | and, instead, use the container_of() macro, found in <linux/kernel.h>: | 80 | and, instead, use the container_of() macro, found in <linux/kernel.h>: |
79 | 81 | ||
80 | container_of(pointer, type, member) | 82 | container_of(pointer, type, member) |
83 | |||
84 | where: | ||
85 | |||
86 | * "pointer" is the pointer to the embedded kobject, | ||
87 | * "type" is the type of the containing structure, and | ||
88 | * "member" is the name of the structure field to which "pointer" points. | ||
89 | |||
90 | The return value from container_of() is a pointer to the corresponding | ||
91 | container type. So, for example, a pointer "kp" to a struct kobject | ||
92 | embedded *within* a struct uio_map could be converted to a pointer to the | ||
93 | *containing* uio_map structure with: | ||
94 | |||
95 | struct uio_map *u_map = container_of(kp, struct uio_map, kobj); | ||
96 | |||
97 | For convenience, programmers often define a simple macro for "back-casting" | ||
98 | kobject pointers to the containing type. Exactly this happens in the | ||
99 | earlier drivers/uio/uio.c, as you can see here: | ||
100 | |||
101 | struct uio_map { | ||
102 | struct kobject kobj; | ||
103 | struct uio_mem *mem; | ||
104 | }; | ||
81 | 105 | ||
82 | where pointer is the pointer to the embedded kobject, type is the type of | 106 | #define to_map(map) container_of(map, struct uio_map, kobj) |
83 | the containing structure, and member is the name of the structure field to | ||
84 | which pointer points. The return value from container_of() is a pointer to | ||
85 | the given type. So, for example, a pointer "kp" to a struct kobject | ||
86 | embedded within a struct uio_mem could be converted to a pointer to the | ||
87 | containing uio_mem structure with: | ||
88 | 107 | ||
89 | struct uio_mem *u_mem = container_of(kp, struct uio_mem, kobj); | 108 | where the macro argument "map" is a pointer to the struct kobject in |
109 | question. That macro is subsequently invoked with: | ||
90 | 110 | ||
91 | Programmers often define a simple macro for "back-casting" kobject pointers | 111 | struct uio_map *map = to_map(kobj); |
92 | to the containing type. | ||
93 | 112 | ||
94 | 113 | ||
95 | Initialization of kobjects | 114 | Initialization of kobjects |
@@ -387,4 +406,5 @@ called, and the objects in the former circle release each other. | |||
387 | Example code to copy from | 406 | Example code to copy from |
388 | 407 | ||
389 | For a more complete example of using ksets and kobjects properly, see the | 408 | For a more complete example of using ksets and kobjects properly, see the |
390 | sample/kobject/kset-example.c code. | 409 | example programs samples/kobject/{kobject-example.c,kset-example.c}, |
410 | which will be built as loadable modules if you select CONFIG_SAMPLE_KOBJECT. | ||
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/stmmac.txt b/Documentation/networking/stmmac.txt new file mode 100644 index 000000000000..7ee770b5ef5f --- /dev/null +++ b/Documentation/networking/stmmac.txt | |||
@@ -0,0 +1,143 @@ | |||
1 | STMicroelectronics 10/100/1000 Synopsys Ethernet driver | ||
2 | |||
3 | Copyright (C) 2007-2010 STMicroelectronics Ltd | ||
4 | Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> | ||
5 | |||
6 | This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers | ||
7 | (Synopsys IP blocks); it has been fully tested on STLinux platforms. | ||
8 | |||
9 | Currently this network device driver is for all STM embedded MAC/GMAC | ||
10 | (7xxx SoCs). | ||
11 | |||
12 | DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100 | ||
13 | Universal version 4.0 have been used for developing the first code | ||
14 | implementation. | ||
15 | |||
16 | Please, for more information also visit: www.stlinux.com | ||
17 | |||
18 | 1) Kernel Configuration | ||
19 | The kernel configuration option is STMMAC_ETH: | ||
20 | Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) ---> | ||
21 | STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH) | ||
22 | |||
23 | 2) Driver parameters list: | ||
24 | debug: message level (0: no output, 16: all); | ||
25 | phyaddr: to manually provide the physical address to the PHY device; | ||
26 | dma_rxsize: DMA rx ring size; | ||
27 | dma_txsize: DMA tx ring size; | ||
28 | buf_sz: DMA buffer size; | ||
29 | tc: control the HW FIFO threshold; | ||
30 | tx_coe: Enable/Disable Tx Checksum Offload engine; | ||
31 | watchdog: transmit timeout (in milliseconds); | ||
32 | flow_ctrl: Flow control ability [on/off]; | ||
33 | pause: Flow Control Pause Time; | ||
34 | tmrate: timer period (only if timer optimisation is configured). | ||
35 | |||
36 | 3) Command line options | ||
37 | Driver parameters can be also passed in command line by using: | ||
38 | stmmaceth=dma_rxsize:128,dma_txsize:512 | ||
39 | |||
40 | 4) Driver information and notes | ||
41 | |||
42 | 4.1) Transmit process | ||
43 | The xmit method is invoked when the kernel needs to transmit a packet; it sets | ||
44 | the descriptors in the ring and informs the DMA engine that there is a packet | ||
45 | ready to be transmitted. | ||
46 | Once the controller has finished transmitting the packet, an interrupt is | ||
47 | triggered; So the driver will be able to release the socket buffers. | ||
48 | By default, the driver sets the NETIF_F_SG bit in the features field of the | ||
49 | net_device structure enabling the scatter/gather feature. | ||
50 | |||
51 | 4.2) Receive process | ||
52 | When one or more packets are received, an interrupt happens. The interrupts | ||
53 | are not queued so the driver has to scan all the descriptors in the ring during | ||
54 | the receive process. | ||
55 | This is based on NAPI so the interrupt handler signals only if there is work to be | ||
56 | done, and it exits. | ||
57 | Then the poll method will be scheduled at some future point. | ||
58 | The incoming packets are stored, by the DMA, in a list of pre-allocated socket | ||
59 | buffers in order to avoid the memcpy (Zero-copy). | ||
60 | |||
61 | 4.3) Timer-Driver Interrupt | ||
62 | Instead of having the device that asynchronously notifies the frame receptions, the | ||
63 | driver configures a timer to generate an interrupt at regular intervals. | ||
64 | Based on the granularity of the timer, the frames that are received by the device | ||
65 | will experience different levels of latency. Some NICs have dedicated timer | ||
66 | device to perform this task. STMMAC can use either the RTC device or the TMU | ||
67 | channel 2 on STLinux platforms. | ||
68 | The timers frequency can be passed to the driver as parameter; when change it, | ||
69 | take care of both hardware capability and network stability/performance impact. | ||
70 | Several performance tests on STM platforms showed this optimisation allows to spare | ||
71 | the CPU while having the maximum throughput. | ||
72 | |||
73 | 4.4) WOL | ||
74 | Wake up on Lan feature through Magic Frame is only supported for the GMAC | ||
75 | core. | ||
76 | |||
77 | 4.5) DMA descriptors | ||
78 | Driver handles both normal and enhanced descriptors. The latter has been only | ||
79 | tested on DWC Ether MAC 10/100/1000 Universal version 3.41a. | ||
80 | |||
81 | 4.6) Ethtool support | ||
82 | Ethtool is supported. Driver statistics and internal errors can be taken using: | ||
83 | ethtool -S ethX command. It is possible to dump registers etc. | ||
84 | |||
85 | 4.7) Jumbo and Segmentation Offloading | ||
86 | Jumbo frames are supported and tested for the GMAC. | ||
87 | The GSO has been also added but it's performed in software. | ||
88 | LRO is not supported. | ||
89 | |||
90 | 4.8) Physical | ||
91 | The driver is compatible with PAL to work with PHY and GPHY devices. | ||
92 | |||
93 | 4.9) Platform information | ||
94 | Several information came from the platform; please refer to the | ||
95 | driver's Header file in include/linux directory. | ||
96 | |||
97 | struct plat_stmmacenet_data { | ||
98 | int bus_id; | ||
99 | int pbl; | ||
100 | int has_gmac; | ||
101 | void (*fix_mac_speed)(void *priv, unsigned int speed); | ||
102 | void (*bus_setup)(unsigned long ioaddr); | ||
103 | #ifdef CONFIG_STM_DRIVERS | ||
104 | struct stm_pad_config *pad_config; | ||
105 | #endif | ||
106 | void *bsp_priv; | ||
107 | }; | ||
108 | |||
109 | Where: | ||
110 | - pbl (Programmable Burst Length) is maximum number of | ||
111 | beats to be transferred in one DMA transaction. | ||
112 | GMAC also enables the 4xPBL by default. | ||
113 | - fix_mac_speed and bus_setup are used to configure internal target | ||
114 | registers (on STM platforms); | ||
115 | - has_gmac: GMAC core is on board (get it at run-time in the next step); | ||
116 | - bus_id: bus identifier. | ||
117 | |||
118 | struct plat_stmmacphy_data { | ||
119 | int bus_id; | ||
120 | int phy_addr; | ||
121 | unsigned int phy_mask; | ||
122 | int interface; | ||
123 | int (*phy_reset)(void *priv); | ||
124 | void *priv; | ||
125 | }; | ||
126 | |||
127 | Where: | ||
128 | - bus_id: bus identifier; | ||
129 | - phy_addr: physical address used for the attached phy device; | ||
130 | set it to -1 to get it at run-time; | ||
131 | - interface: physical MII interface mode; | ||
132 | - phy_reset: hook to reset HW function. | ||
133 | |||
134 | TODO: | ||
135 | - Continue to make the driver more generic and suitable for other Synopsys | ||
136 | Ethernet controllers used on other architectures (i.e. ARM). | ||
137 | - 10G controllers are not supported. | ||
138 | - MAC uses Normal descriptors and GMAC uses enhanced ones. | ||
139 | This is a limit that should be reviewed. MAC could want to | ||
140 | use the enhanced structure. | ||
141 | - Checksumming: Rx/Tx csum is done in HW in case of GMAC only. | ||
142 | - Review the timer optimisation code to use an embedded device that seems to be | ||
143 | available in new chip generations. | ||
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/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: |