Lines Matching refs:stall
3 The rcu_cpu_stall_suppress module parameter enables RCU's CPU stall
5 This module parameter enables CPU stall detection by default, but
7 The stall detector's idea of what constitutes "unduly delayed" is
14 issues an RCU CPU stall warning. This time period is normally
20 So if you are 10 seconds into a 40-second stall, setting this
22 -next- stall, or the following warning for the current stall
23 (assuming the stall lasts long enough). It will not affect the
24 timing of the next warning for the current stall.
34 giving an RCU CPU stall warning message. (This is a cpp
39 The CPU stall detector tries to make the offending CPU print its
41 However, if the offending CPU does not detect its own stall in
49 This boot/sysfs parameter controls the RCU-tasks stall warning
50 interval. A value of zero or less suppresses RCU-tasks stall
51 warnings. A positive value sets the stall-warning interval
52 in jiffies. An RCU-tasks stall warning starts wtih the line:
62 INFO: rcu_sched_state detected stall on CPU 5 (t=2500 jiffies)
64 This message indicates that CPU 5 detected that it was causing a stall,
65 and that the stall was affecting RCU-sched. This message will normally be
71 On the other hand, if the offending CPU fails to print out a stall-warning
78 causing stalls, and that the stall was affecting RCU-bh. This message
82 It is even possible for a rcu_preempt_state stall to be caused by both
86 Finally, if the grace period ends just as the stall warning starts
87 printing, there will be a spurious stall-warning message:
92 possible for a zero-jiffy stall to be flagged in this case, depending
93 on how the stall warning and the grace-period initialization happen to
98 Recent kernels will print a long form of the stall-warning message:
100 INFO: rcu_preempt detected stall on CPU
106 INFO: rcu_preempt detected stall on CPU
132 across repeated stall-warning messages, it is possible that RCU's softirq
148 the stall warning, the following additional line is printed:
153 RCU CPU stall warnings even when all CPUs and tasks have passed through
159 If a stall lasts long enough, multiple stall-warning messages will be
163 of the stall and the first message.
168 If an expedited grace period detects a stall, it will place a message
179 It is entirely possible to see stall warnings from normal and from
185 So your kernel printed an RCU CPU stall warning. The next question is
186 "What caused it?" The following problems can result in RCU CPU stall
203 does not necessarily prevent RCU CPU stall warnings. Therefore,
212 RCU CPU stall warning messages. Especially if you have added
227 memory, you might see stall-warning messages.
235 CONFIG_PREEMPT_RCU case, you might see stall-warning
241 result in RCU CPU stall warnings for CONFIG_NO_HZ_COMMON=n kernels.
248 This resulted in a series of RCU CPU stall warnings, eventually
251 The RCU, RCU-sched, RCU-bh, and RCU-tasks implementations have CPU stall
252 warning. Note that SRCU does -not- have CPU stall warnings. Please note
254 No grace period, no CPU stall warnings.
256 To diagnose the cause of the stall, inspect the stack traces.
258 If you have a series of stall warnings from a single extended stall,
259 comparing the stack traces can often help determine where the stall
262 If you can reliably trigger the stall, ftrace can be quite helpful.