diff options
Diffstat (limited to 'Documentation/RCU/torture.txt')
| -rw-r--r-- | Documentation/RCU/torture.txt | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt index 118e7c176ce7..55918b54808b 100644 --- a/Documentation/RCU/torture.txt +++ b/Documentation/RCU/torture.txt @@ -10,21 +10,6 @@ status messages via printk(), which can be examined via the dmesg command (perhaps grepping for "torture"). The test is started when the module is loaded, and stops when the module is unloaded. -CONFIG_RCU_TORTURE_TEST_RUNNABLE - -It is also possible to specify CONFIG_RCU_TORTURE_TEST=y, which will -result in the tests being loaded into the base kernel. In this case, -the CONFIG_RCU_TORTURE_TEST_RUNNABLE config option is used to specify -whether the RCU torture tests are to be started immediately during -boot or whether the /proc/sys/kernel/rcutorture_runnable file is used -to enable them. This /proc file can be used to repeatedly pause and -restart the tests, regardless of the initial state specified by the -CONFIG_RCU_TORTURE_TEST_RUNNABLE config option. - -You will normally -not- want to start the RCU torture tests during boot -(and thus the default is CONFIG_RCU_TORTURE_TEST_RUNNABLE=n), but doing -this can sometimes be useful in finding boot-time bugs. - MODULE PARAMETERS @@ -291,15 +276,17 @@ o "Free-Block Circulation": Shows the number of torture structures somehow gets incremented farther than it should. Different implementations of RCU can provide implementation-specific -additional information. For example, SRCU provides the following +additional information. For example, Tree SRCU provides the following additional line: - srcu-torture: per-CPU(idx=1): 0(0,1) 1(0,1) 2(0,0) 3(0,1) + srcud-torture: Tree SRCU per-CPU(idx=0): 0(35,-21) 1(-4,24) 2(1,1) 3(-26,20) 4(28,-47) 5(-9,4) 6(-10,14) 7(-14,11) T(1,6) -This line shows the per-CPU counter state. The numbers in parentheses are -the values of the "old" and "current" counters for the corresponding CPU. -The "idx" value maps the "old" and "current" values to the underlying -array, and is useful for debugging. +This line shows the per-CPU counter state, in this case for Tree SRCU +using a dynamically allocated srcu_struct (hence "srcud-" rather than +"srcu-"). The numbers in parentheses are the values of the "old" and +"current" counters for the corresponding CPU. The "idx" value maps the +"old" and "current" values to the underlying array, and is useful for +debugging. The final "T" entry contains the totals of the counters. USAGE @@ -319,3 +306,9 @@ checked for such errors. The "rmmod" command forces a "SUCCESS", "FAILURE", or "RCU_HOTPLUG" indication to be printk()ed. The first two are self-explanatory, while the last indicates that while there were no RCU failures, CPU-hotplug problems were detected. + +However, the tools/testing/selftests/rcutorture/bin/kvm.sh script +provides better automation, including automatic failure analysis. +It assumes a qemu/kvm-enabled platform, and runs guest OSes out of initrd. +See tools/testing/selftests/rcutorture/doc/initrd.txt for instructions +on setting up such an initrd. |