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authorPaul E. McKenney <paul.mckenney@linaro.org>2012-02-20 17:51:45 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-04-30 10:48:18 -0700
commitfae4b54f28f034d228fa3bfc98858c698b64e89c (patch)
tree1259258956ba9d30eba6360083214e145ec19813 /Documentation/RCU
parent37e377d2823e03528cb64f435d7c0e30b1c668eb (diff)
rcu: Introduce rcutorture testing for rcu_barrier()
Although rcutorture does invoke rcu_barrier() and friends, it cannot really be called a torture test given that it invokes them only once at the end of the test. This commit therefore introduces heavy-duty rcutorture testing for rcu_barrier(), which may be carried out concurrently with normal rcutorture testing. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU')
-rw-r--r--Documentation/RCU/torture.txt15
1 files changed, 14 insertions, 1 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 375d3fb71437..4ddf3913fd8c 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -47,6 +47,16 @@ irqreader Says to invoke RCU readers from irq level. This is currently
permit this. (Or, more accurately, variants of RCU that do
-not- permit this know to ignore this variable.)
+n_barrier_cbs If this is nonzero, RCU barrier testing will be conducted,
+ in which case n_barrier_cbs specifies the number of
+ RCU callbacks (and corresponding kthreads) to use for
+ this testing. The value cannot be negative. If you
+ specify this to be non-zero when torture_type indicates a
+ synchronous RCU implementation (one for which a member of
+ the synchronize_rcu() rather than the call_rcu() family is
+ used -- see the documentation for torture_type below), an
+ error will be reported and no testing will be carried out.
+
nfakewriters This is the number of RCU fake writer threads to run. Fake
writer threads repeatedly use the synchronous "wait for
current readers" function of the interface selected by
@@ -188,7 +198,7 @@ OUTPUT
The statistics output is as follows:
rcu-torture:--- Start of test: nreaders=16 nfakewriters=4 stat_interval=30 verbose=0 test_no_idle_hz=1 shuffle_interval=3 stutter=5 irqreader=1 fqs_duration=0 fqs_holdoff=0 fqs_stutter=3 test_boost=1/0 test_boost_interval=7 test_boost_duration=4
- rcu-torture: rtc: (null) ver: 155441 tfle: 0 rta: 155441 rtaf: 8884 rtf: 155440 rtmbe: 0 rtbke: 0 rtbre: 0 rtbf: 0 rtb: 0 nt: 3055767
+ rcu-torture: rtc: (null) ver: 155441 tfle: 0 rta: 155441 rtaf: 8884 rtf: 155440 rtmbe: 0 rtbe: 0 rtbke: 0 rtbre: 0 rtbf: 0 rtb: 0 nt: 3055767
rcu-torture: Reader Pipe: 727860534 34213 0 0 0 0 0 0 0 0 0
rcu-torture: Reader Batch: 727877838 17003 0 0 0 0 0 0 0 0 0
rcu-torture: Free-Block Circulation: 155440 155440 155440 155440 155440 155440 155440 155440 155440 155440 0
@@ -230,6 +240,9 @@ o "rtmbe": A non-zero value indicates that rcutorture believes that
rcu_assign_pointer() and rcu_dereference() are not working
correctly. This value should be zero.
+o "rtbe": A non-zero value indicates that one of the rcu_barrier()
+ family of functions is not working correctly.
+
o "rtbke": rcutorture was unable to create the real-time kthreads
used to force RCU priority inversion. This value should be zero.

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