Lines Matching refs:in
41 However, if the offending CPU does not detect its own stall in
52 in jiffies. An RCU-tasks stall warning starts wtih the line:
83 CPUs -and- tasks, in which case the offending CPUs and tasks will all
84 be called out in the list.
91 This is rare, but does happen from time to time in real life. It is also
92 possible for a zero-jiffy stall to be flagged in this case, depending
119 in dyntick-idle mode and an odd-numbered value otherwise. The hex
121 be a small positive number if in the idle loop and a very large positive
129 example, if the CPU might have been in dyntick-idle mode for an extended
134 the stalled CPU is spinning with interrupts are disabled, or, in -rt
138 low-order 16 bits (in hex) of the jiffies counter when this CPU last
152 Starving the grace-period kthreads of CPU time can of course result in
169 like the following in dmesg:
177 grace period is in flight.
186 "What caused it?" The following problems can result in RCU CPU stall
189 o A CPU looping in an RCU read-side critical section.
192 result in RCU-sched and RCU-bh stalls.
195 result in RCU-sched stalls and, if ksoftirqd is in use, RCU-bh
199 result in RCU-sched and RCU-bh stalls.
201 o For !CONFIG_PREEMPT kernels, a CPU looping anywhere in the
204 if the looping in the kernel is really expected and desirable
211 with boot-time message rates, and will frequently result in
216 This can result in the "All QSes seen" console-log message.
220 o A CPU-bound real-time task in a CONFIG_PREEMPT kernel, which might
221 happen to preempt a low-priority task in the middle of an RCU
224 in which case the next RCU grace period can never complete, which
226 While the system is in the process of running itself out of
229 o A CPU-bound real-time task in a CONFIG_PREEMPT_RT kernel that
232 and in a CONFIG_PREEMPT_RCU kernel will further prevent
239 interrupt on a CPU that is not in dyntick-idle mode. This
241 result in RCU CPU stall warnings for CONFIG_NO_HZ_COMMON=n kernels.
243 o A bug in the RCU implementation.
246 at least once in real life. A CPU failed in a running system,
248 This resulted in a series of RCU CPU stall warnings, eventually
253 that RCU only detects CPU stalls when there is a grace period in progress.
260 is occurring, which will usually be in the function nearest the top of