aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorAnton Altaparmakov <aia21@cantab.net>2005-10-31 05:06:46 -0500
committerAnton Altaparmakov <aia21@cantab.net>2005-10-31 05:06:46 -0500
commit1f04c0a24b2f3cfe89c802a24396263623e3512d (patch)
treed7e2216b6e65b833c0c2b79b478d13ce17dbf296 /Documentation
parent07b188ab773e183871e57b33ae37bf635c9f12ba (diff)
parente2f2e58e7968f8446b1078a20a18bf8ea12b4fbc (diff)
Merge branch 'master' of /usr/src/ntfs-2.6/
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/RCU/torture.txt122
-rw-r--r--Documentation/cpusets.txt2
-rw-r--r--Documentation/firmware_class/firmware_sample_driver.c1
-rw-r--r--Documentation/firmware_class/firmware_sample_firmware_class.c2
-rw-r--r--Documentation/i2c/writing-clients1
-rw-r--r--Documentation/keys.txt22
6 files changed, 140 insertions, 10 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
new file mode 100644
index 000000000000..e4c38152f7f7
--- /dev/null
+++ b/Documentation/RCU/torture.txt
@@ -0,0 +1,122 @@
1RCU Torture Test Operation
2
3
4CONFIG_RCU_TORTURE_TEST
5
6The CONFIG_RCU_TORTURE_TEST config option is available for all RCU
7implementations. It creates an rcutorture kernel module that can
8be loaded to run a torture test. The test periodically outputs
9status messages via printk(), which can be examined via the dmesg
10command (perhaps grepping for "rcutorture"). The test is started
11when the module is loaded, and stops when the module is unloaded.
12
13However, actually setting this config option to "y" results in the system
14running the test immediately upon boot, and ending only when the system
15is taken down. Normally, one will instead want to build the system
16with CONFIG_RCU_TORTURE_TEST=m and to use modprobe and rmmod to control
17the test, perhaps using a script similar to the one shown at the end of
18this document. Note that you will need CONFIG_MODULE_UNLOAD in order
19to be able to end the test.
20
21
22MODULE PARAMETERS
23
24This module has the following parameters:
25
26nreaders This is the number of RCU reading threads supported.
27 The default is twice the number of CPUs. Why twice?
28 To properly exercise RCU implementations with preemptible
29 read-side critical sections.
30
31stat_interval The number of seconds between output of torture
32 statistics (via printk()). Regardless of the interval,
33 statistics are printed when the module is unloaded.
34 Setting the interval to zero causes the statistics to
35 be printed -only- when the module is unloaded, and this
36 is the default.
37
38verbose Enable debug printk()s. Default is disabled.
39
40
41OUTPUT
42
43The statistics output is as follows:
44
45 rcutorture: --- Start of test: nreaders=16 stat_interval=0 verbose=0
46 rcutorture: rtc: 0000000000000000 ver: 1916 tfle: 0 rta: 1916 rtaf: 0 rtf: 1915
47 rcutorture: Reader Pipe: 1466408 9747 0 0 0 0 0 0 0 0 0
48 rcutorture: Reader Batch: 1464477 11678 0 0 0 0 0 0 0 0
49 rcutorture: Free-Block Circulation: 1915 1915 1915 1915 1915 1915 1915 1915 1915 1915 0
50 rcutorture: --- End of test
51
52The command "dmesg | grep rcutorture:" will extract this information on
53most systems. On more esoteric configurations, it may be necessary to
54use other commands to access the output of the printk()s used by
55the RCU torture test. The printk()s use KERN_ALERT, so they should
56be evident. ;-)
57
58The entries are as follows:
59
60o "ggp": The number of counter flips (or batches) since boot.
61
62o "rtc": The hexadecimal address of the structure currently visible
63 to readers.
64
65o "ver": The number of times since boot that the rcutw writer task
66 has changed the structure visible to readers.
67
68o "tfle": If non-zero, indicates that the "torture freelist"
69 containing structure to be placed into the "rtc" area is empty.
70 This condition is important, since it can fool you into thinking
71 that RCU is working when it is not. :-/
72
73o "rta": Number of structures allocated from the torture freelist.
74
75o "rtaf": Number of allocations from the torture freelist that have
76 failed due to the list being empty.
77
78o "rtf": Number of frees into the torture freelist.
79
80o "Reader Pipe": Histogram of "ages" of structures seen by readers.
81 If any entries past the first two are non-zero, RCU is broken.
82 And rcutorture prints the error flag string "!!!" to make sure
83 you notice. The age of a newly allocated structure is zero,
84 it becomes one when removed from reader visibility, and is
85 incremented once per grace period subsequently -- and is freed
86 after passing through (RCU_TORTURE_PIPE_LEN-2) grace periods.
87
88 The output displayed above was taken from a correctly working
89 RCU. If you want to see what it looks like when broken, break
90 it yourself. ;-)
91
92o "Reader Batch": Another histogram of "ages" of structures seen
93 by readers, but in terms of counter flips (or batches) rather
94 than in terms of grace periods. The legal number of non-zero
95 entries is again two. The reason for this separate view is
96 that it is easier to get the third entry to show up in the
97 "Reader Batch" list than in the "Reader Pipe" list.
98
99o "Free-Block Circulation": Shows the number of torture structures
100 that have reached a given point in the pipeline. The first element
101 should closely correspond to the number of structures allocated,
102 the second to the number that have been removed from reader view,
103 and all but the last remaining to the corresponding number of
104 passes through a grace period. The last entry should be zero,
105 as it is only incremented if a torture structure's counter
106 somehow gets incremented farther than it should.
107
108
109USAGE
110
111The following script may be used to torture RCU:
112
113 #!/bin/sh
114
115 modprobe rcutorture
116 sleep 100
117 rmmod rcutorture
118 dmesg | grep rcutorture:
119
120The output can be manually inspected for the error flag of "!!!".
121One could of course create a more elaborate script that automatically
122checked for such errors.
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index d17b7d2dd771..a09a8eb80665 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -94,7 +94,7 @@ the available CPU and Memory resources amongst the requesting tasks.
94But larger systems, which benefit more from careful processor and 94But larger systems, which benefit more from careful processor and
95memory placement to reduce memory access times and contention, 95memory placement to reduce memory access times and contention,
96and which typically represent a larger investment for the customer, 96and which typically represent a larger investment for the customer,
97can benefit from explictly placing jobs on properly sized subsets of 97can benefit from explicitly placing jobs on properly sized subsets of
98the system. 98the system.
99 99
100This can be especially valuable on: 100This can be especially valuable on:
diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c
index 4bef8c25172c..d3ad2c24490a 100644
--- a/Documentation/firmware_class/firmware_sample_driver.c
+++ b/Documentation/firmware_class/firmware_sample_driver.c
@@ -13,6 +13,7 @@
13#include <linux/kernel.h> 13#include <linux/kernel.h>
14#include <linux/init.h> 14#include <linux/init.h>
15#include <linux/device.h> 15#include <linux/device.h>
16#include <linux/string.h>
16 17
17#include "linux/firmware.h" 18#include "linux/firmware.h"
18 19
diff --git a/Documentation/firmware_class/firmware_sample_firmware_class.c b/Documentation/firmware_class/firmware_sample_firmware_class.c
index 09eab2f1b373..57b956aecbc5 100644
--- a/Documentation/firmware_class/firmware_sample_firmware_class.c
+++ b/Documentation/firmware_class/firmware_sample_firmware_class.c
@@ -14,6 +14,8 @@
14#include <linux/module.h> 14#include <linux/module.h>
15#include <linux/init.h> 15#include <linux/init.h>
16#include <linux/timer.h> 16#include <linux/timer.h>
17#include <linux/slab.h>
18#include <linux/string.h>
17#include <linux/firmware.h> 19#include <linux/firmware.h>
18 20
19 21
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index e94d9c6cc522..cff7b652588a 100644
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -273,6 +273,7 @@ For now, you can ignore the `flags' parameter. It is there for future use.
273 if (is_isa) { 273 if (is_isa) {
274 274
275 /* Discard immediately if this ISA range is already used */ 275 /* Discard immediately if this ISA range is already used */
276 /* FIXME: never use check_region(), only request_region() */
276 if (check_region(address,FOO_EXTENT)) 277 if (check_region(address,FOO_EXTENT))
277 goto ERROR0; 278 goto ERROR0;
278 279
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 4afe03a58c5b..31154882000a 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -196,7 +196,7 @@ KEY ACCESS PERMISSIONS
196 196
197Keys have an owner user ID, a group access ID, and a permissions mask. The mask 197Keys have an owner user ID, a group access ID, and a permissions mask. The mask
198has up to eight bits each for possessor, user, group and other access. Only 198has up to eight bits each for possessor, user, group and other access. Only
199five of each set of eight bits are defined. These permissions granted are: 199six of each set of eight bits are defined. These permissions granted are:
200 200
201 (*) View 201 (*) View
202 202
@@ -224,6 +224,10 @@ five of each set of eight bits are defined. These permissions granted are:
224 keyring to a key, a process must have Write permission on the keyring and 224 keyring to a key, a process must have Write permission on the keyring and
225 Link permission on the key. 225 Link permission on the key.
226 226
227 (*) Set Attribute
228
229 This permits a key's UID, GID and permissions mask to be changed.
230
227For changing the ownership, group ID or permissions mask, being the owner of 231For changing the ownership, group ID or permissions mask, being the owner of
228the key or having the sysadmin capability is sufficient. 232the key or having the sysadmin capability is sufficient.
229 233
@@ -242,15 +246,15 @@ about the status of the key service:
242 this way: 246 this way:
243 247
244 SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY 248 SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY
245 00000001 I----- 39 perm 1f1f0000 0 0 keyring _uid_ses.0: 1/4 249 00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4
246 00000002 I----- 2 perm 1f1f0000 0 0 keyring _uid.0: empty 250 00000002 I----- 2 perm 1f3f0000 0 0 keyring _uid.0: empty
247 00000007 I----- 1 perm 1f1f0000 0 0 keyring _pid.1: empty 251 00000007 I----- 1 perm 1f3f0000 0 0 keyring _pid.1: empty
248 0000018d I----- 1 perm 1f1f0000 0 0 keyring _pid.412: empty 252 0000018d I----- 1 perm 1f3f0000 0 0 keyring _pid.412: empty
249 000004d2 I--Q-- 1 perm 1f1f0000 32 -1 keyring _uid.32: 1/4 253 000004d2 I--Q-- 1 perm 1f3f0000 32 -1 keyring _uid.32: 1/4
250 000004d3 I--Q-- 3 perm 1f1f0000 32 -1 keyring _uid_ses.32: empty 254 000004d3 I--Q-- 3 perm 1f3f0000 32 -1 keyring _uid_ses.32: empty
251 00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0 255 00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0
252 00000893 I--Q-N 1 35s 1f1f0000 0 0 user metal:silver: 0 256 00000893 I--Q-N 1 35s 1f3f0000 0 0 user metal:silver: 0
253 00000894 I--Q-- 1 10h 001f0000 0 0 user metal:gold: 0 257 00000894 I--Q-- 1 10h 003f0000 0 0 user metal:gold: 0
254 258
255 The flags are: 259 The flags are:
256 260