Lines Matching refs:stall

3 This document first discusses what sorts of issues RCU's CPU stall
6 this document explains the stall detector's "splat" format.
11 So your kernel printed an RCU CPU stall warning.  The next question is
12 "What caused it?"  The following problems can result in RCU CPU stall
32 	RCU CPU stall warning messages.  Especially if you have added
49 	memory, you might see stall-warning messages.
57 	CONFIG_PREEMPT_RCU case, you might see stall-warning
72 	RCU CPU stall warnings.
74 o	Testing a workload on a fast system, tuning the stall-warning
75 	timeout down to just barely avoid RCU CPU stall warnings, and then
76 	running the same workload with the same stall-warning timeout on a
83 	result in RCU CPU stall warnings for CONFIG_NO_HZ_COMMON=n kernels.
90 	This resulted in a series of RCU CPU stall warnings, eventually
93 The RCU, RCU-sched, and RCU-tasks implementations have CPU stall warning.
94 Note that SRCU does -not- have CPU stall warnings.  Please note that
96 No grace period, no CPU stall warnings.
98 To diagnose the cause of the stall, inspect the stack traces.
100 If you have a series of stall warnings from a single extended stall,
101 comparing the stack traces can often help determine where the stall
104 If you can reliably trigger the stall, ftrace can be quite helpful.
114 CPU stall detector, which detects conditions that unduly delay RCU grace
115 periods.  This module parameter enables CPU stall detection by default,
117 The stall detector's idea of what constitutes "unduly delayed" is
124 	issues an RCU CPU stall warning.  This time period is normally
130 	So if you are 10 seconds into a 40-second stall, setting this
132 	-next- stall, or the following warning for the current stall
133 	(assuming the stall lasts long enough).  It will not affect the
134 	timing of the next warning for the current stall.
144 	giving an RCU CPU stall warning message.  (This is a cpp
149 	The CPU stall detector tries to make the offending CPU print its
151 	However, if the offending CPU does not detect its own stall in
159 	This boot/sysfs parameter controls the RCU-tasks stall warning
160 	interval.  A value of zero or less suppresses RCU-tasks stall
161 	warnings.  A positive value sets the stall-warning interval
162 	in seconds.  An RCU-tasks stall warning starts with the line:
181 causing stalls, and that the stall was affecting RCU-sched.  This message
185 possible for an rcu_state stall to be caused by both CPUs -and- tasks,
209 across repeated stall-warning messages, it is possible that RCU's softirq
219 The "detected by" line indicates which CPU detected the stall (in this
241 If the grace period ends just as the stall warning starts printing,
242 there will be a spurious stall-warning message, which will include
248 possible for a zero-jiffy stall to be flagged in this case, depending
249 on how the stall warning and the grace-period initialization happen to
255 grace period has nevertheless failed to end, the stall-warning splat
268 the stall warning, as was the case in the "All QSes seen" line above,
274 in RCU CPU stall warnings even when all CPUs and tasks have passed
285 If a stall lasts long enough, multiple stall-warning messages will be
289 of the stall and the first message.
294 If an expedited grace period detects a stall, it will place a message
320 It is entirely possible to see stall warnings from normal and from