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author | Anton Altaparmakov <aia21@cantab.net> | 2005-10-31 10:06:46 (GMT) |
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committer | Anton Altaparmakov <aia21@cantab.net> | 2005-10-31 10:06:46 (GMT) |
commit | 1f04c0a24b2f3cfe89c802a24396263623e3512d (patch) | |
tree | d7e2216b6e65b833c0c2b79b478d13ce17dbf296 /Documentation | |
parent | 07b188ab773e183871e57b33ae37bf635c9f12ba (diff) | |
parent | e2f2e58e7968f8446b1078a20a18bf8ea12b4fbc (diff) | |
download | linux-1f04c0a24b2f3cfe89c802a24396263623e3512d.tar.xz |
Merge branch 'master' of /usr/src/ntfs-2.6/
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/RCU/torture.txt | 122 | ||||
-rw-r--r-- | Documentation/cpusets.txt | 2 | ||||
-rw-r--r-- | Documentation/firmware_class/firmware_sample_driver.c | 1 | ||||
-rw-r--r-- | Documentation/firmware_class/firmware_sample_firmware_class.c | 2 | ||||
-rw-r--r-- | Documentation/i2c/writing-clients | 1 | ||||
-rw-r--r-- | Documentation/keys.txt | 22 |
6 files changed, 140 insertions, 10 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt new file mode 100644 index 0000000..e4c3815 --- /dev/null +++ b/Documentation/RCU/torture.txt @@ -0,0 +1,122 @@ +RCU Torture Test Operation + + +CONFIG_RCU_TORTURE_TEST + +The CONFIG_RCU_TORTURE_TEST config option is available for all RCU +implementations. It creates an rcutorture kernel module that can +be loaded to run a torture test. The test periodically outputs +status messages via printk(), which can be examined via the dmesg +command (perhaps grepping for "rcutorture"). The test is started +when the module is loaded, and stops when the module is unloaded. + +However, actually setting this config option to "y" results in the system +running the test immediately upon boot, and ending only when the system +is taken down. Normally, one will instead want to build the system +with CONFIG_RCU_TORTURE_TEST=m and to use modprobe and rmmod to control +the test, perhaps using a script similar to the one shown at the end of +this document. Note that you will need CONFIG_MODULE_UNLOAD in order +to be able to end the test. + + +MODULE PARAMETERS + +This module has the following parameters: + +nreaders This is the number of RCU reading threads supported. + The default is twice the number of CPUs. Why twice? + To properly exercise RCU implementations with preemptible + read-side critical sections. + +stat_interval The number of seconds between output of torture + statistics (via printk()). Regardless of the interval, + statistics are printed when the module is unloaded. + Setting the interval to zero causes the statistics to + be printed -only- when the module is unloaded, and this + is the default. + +verbose Enable debug printk()s. Default is disabled. + + +OUTPUT + +The statistics output is as follows: + + rcutorture: --- Start of test: nreaders=16 stat_interval=0 verbose=0 + rcutorture: rtc: 0000000000000000 ver: 1916 tfle: 0 rta: 1916 rtaf: 0 rtf: 1915 + rcutorture: Reader Pipe: 1466408 9747 0 0 0 0 0 0 0 0 0 + rcutorture: Reader Batch: 1464477 11678 0 0 0 0 0 0 0 0 + rcutorture: Free-Block Circulation: 1915 1915 1915 1915 1915 1915 1915 1915 1915 1915 0 + rcutorture: --- End of test + +The command "dmesg | grep rcutorture:" will extract this information on +most systems. On more esoteric configurations, it may be necessary to +use other commands to access the output of the printk()s used by +the RCU torture test. The printk()s use KERN_ALERT, so they should +be evident. ;-) + +The entries are as follows: + +o "ggp": The number of counter flips (or batches) since boot. + +o "rtc": The hexadecimal address of the structure currently visible + to readers. + +o "ver": The number of times since boot that the rcutw writer task + has changed the structure visible to readers. + +o "tfle": If non-zero, indicates that the "torture freelist" + containing structure to be placed into the "rtc" area is empty. + This condition is important, since it can fool you into thinking + that RCU is working when it is not. :-/ + +o "rta": Number of structures allocated from the torture freelist. + +o "rtaf": Number of allocations from the torture freelist that have + failed due to the list being empty. + +o "rtf": Number of frees into the torture freelist. + +o "Reader Pipe": Histogram of "ages" of structures seen by readers. + If any entries past the first two are non-zero, RCU is broken. + And rcutorture prints the error flag string "!!!" to make sure + you notice. The age of a newly allocated structure is zero, + it becomes one when removed from reader visibility, and is + incremented once per grace period subsequently -- and is freed + after passing through (RCU_TORTURE_PIPE_LEN-2) grace periods. + + The output displayed above was taken from a correctly working + RCU. If you want to see what it looks like when broken, break + it yourself. ;-) + +o "Reader Batch": Another histogram of "ages" of structures seen + by readers, but in terms of counter flips (or batches) rather + than in terms of grace periods. The legal number of non-zero + entries is again two. The reason for this separate view is + that it is easier to get the third entry to show up in the + "Reader Batch" list than in the "Reader Pipe" list. + +o "Free-Block Circulation": Shows the number of torture structures + that have reached a given point in the pipeline. The first element + should closely correspond to the number of structures allocated, + the second to the number that have been removed from reader view, + and all but the last remaining to the corresponding number of + passes through a grace period. The last entry should be zero, + as it is only incremented if a torture structure's counter + somehow gets incremented farther than it should. + + +USAGE + +The following script may be used to torture RCU: + + #!/bin/sh + + modprobe rcutorture + sleep 100 + rmmod rcutorture + dmesg | grep rcutorture: + +The output can be manually inspected for the error flag of "!!!". +One could of course create a more elaborate script that automatically +checked for such errors. diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index d17b7d2..a09a8eb 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt @@ -94,7 +94,7 @@ the available CPU and Memory resources amongst the requesting tasks. But larger systems, which benefit more from careful processor and memory placement to reduce memory access times and contention, and which typically represent a larger investment for the customer, -can benefit from explictly placing jobs on properly sized subsets of +can benefit from explicitly placing jobs on properly sized subsets of the system. This can be especially valuable on: diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c index 4bef8c2..d3ad2c2 100644 --- a/Documentation/firmware_class/firmware_sample_driver.c +++ b/Documentation/firmware_class/firmware_sample_driver.c @@ -13,6 +13,7 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/device.h> +#include <linux/string.h> #include "linux/firmware.h" diff --git a/Documentation/firmware_class/firmware_sample_firmware_class.c b/Documentation/firmware_class/firmware_sample_firmware_class.c index 09eab2f..57b956a 100644 --- a/Documentation/firmware_class/firmware_sample_firmware_class.c +++ b/Documentation/firmware_class/firmware_sample_firmware_class.c @@ -14,6 +14,8 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/timer.h> +#include <linux/slab.h> +#include <linux/string.h> #include <linux/firmware.h> diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index e94d9c6..cff7b65 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. if (is_isa) { /* Discard immediately if this ISA range is already used */ + /* FIXME: never use check_region(), only request_region() */ if (check_region(address,FOO_EXTENT)) goto ERROR0; diff --git a/Documentation/keys.txt b/Documentation/keys.txt index 4afe03a..3115488 100644 --- a/Documentation/keys.txt +++ b/Documentation/keys.txt @@ -196,7 +196,7 @@ KEY ACCESS PERMISSIONS Keys have an owner user ID, a group access ID, and a permissions mask. The mask has up to eight bits each for possessor, user, group and other access. Only -five of each set of eight bits are defined. These permissions granted are: +six of each set of eight bits are defined. These permissions granted are: (*) View @@ -224,6 +224,10 @@ five of each set of eight bits are defined. These permissions granted are: keyring to a key, a process must have Write permission on the keyring and Link permission on the key. + (*) Set Attribute + + This permits a key's UID, GID and permissions mask to be changed. + For changing the ownership, group ID or permissions mask, being the owner of the key or having the sysadmin capability is sufficient. @@ -242,15 +246,15 @@ about the status of the key service: this way: SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY - 00000001 I----- 39 perm 1f1f0000 0 0 keyring _uid_ses.0: 1/4 - 00000002 I----- 2 perm 1f1f0000 0 0 keyring _uid.0: empty - 00000007 I----- 1 perm 1f1f0000 0 0 keyring _pid.1: empty - 0000018d I----- 1 perm 1f1f0000 0 0 keyring _pid.412: empty - 000004d2 I--Q-- 1 perm 1f1f0000 32 -1 keyring _uid.32: 1/4 - 000004d3 I--Q-- 3 perm 1f1f0000 32 -1 keyring _uid_ses.32: empty + 00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4 + 00000002 I----- 2 perm 1f3f0000 0 0 keyring _uid.0: empty + 00000007 I----- 1 perm 1f3f0000 0 0 keyring _pid.1: empty + 0000018d I----- 1 perm 1f3f0000 0 0 keyring _pid.412: empty + 000004d2 I--Q-- 1 perm 1f3f0000 32 -1 keyring _uid.32: 1/4 + 000004d3 I--Q-- 3 perm 1f3f0000 32 -1 keyring _uid_ses.32: empty 00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0 - 00000893 I--Q-N 1 35s 1f1f0000 0 0 user metal:silver: 0 - 00000894 I--Q-- 1 10h 001f0000 0 0 user metal:gold: 0 + 00000893 I--Q-N 1 35s 1f3f0000 0 0 user metal:silver: 0 + 00000894 I--Q-- 1 10h 003f0000 0 0 user metal:gold: 0 The flags are: |