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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-06-11 15:22:43 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-07-17 14:58:44 -0700
commit75c27f119b6475d95374bdad872c6938b5c26196 (patch)
tree2237d56548ca07707fe743a662e693b4cf3f429b /Documentation/RCU
parent9b683874504a57cfa97558d403c75e286e20c9ce (diff)
rcu: Remove CONFIG_RCU_CPU_STALL_INFO
The CONFIG_RCU_CPU_STALL_INFO has been default-y for a couple of releases with no complaints, so it is time to eliminate this Kconfig option entirely, so that the long-form RCU CPU stall warnings cannot be disabled. This commit does just that. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU')
-rw-r--r--Documentation/RCU/stallwarn.txt12
1 files changed, 2 insertions, 10 deletions
diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt
index b57c0c1cdac6..046f32637b95 100644
--- a/Documentation/RCU/stallwarn.txt
+++ b/Documentation/RCU/stallwarn.txt
@@ -26,12 +26,6 @@ CONFIG_RCU_CPU_STALL_TIMEOUT
Stall-warning messages may be enabled and disabled completely via
/sys/module/rcupdate/parameters/rcu_cpu_stall_suppress.
-CONFIG_RCU_CPU_STALL_INFO
-
- This kernel configuration parameter causes the stall warning to
- print out additional per-CPU diagnostic information, including
- information on scheduling-clock ticks and RCU's idle-CPU tracking.
-
RCU_STALL_DELAY_DELTA
Although the lockdep facility is extremely useful, it does add
@@ -101,15 +95,13 @@ interact. Please note that it is not possible to entirely eliminate this
sort of false positive without resorting to things like stop_machine(),
which is overkill for this sort of problem.
-If the CONFIG_RCU_CPU_STALL_INFO kernel configuration parameter is set,
-more information is printed with the stall-warning message, for example:
+Recent kernels will print a long form of the stall-warning message:
INFO: rcu_preempt detected stall on CPU
0: (63959 ticks this GP) idle=241/3fffffffffffffff/0 softirq=82/543
(t=65000 jiffies)
-In kernels with CONFIG_RCU_FAST_NO_HZ, even more information is
-printed:
+In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed:
INFO: rcu_preempt detected stall on CPU
0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 nonlazy_posted: 25 .D