Documentation/RCU/stallwarn.rst

40 -	Anything that prevents RCU's grace-period kthreads from running.
51 	in which case the next RCU grace period can never complete, which
107 RCU only detects CPU stalls when there is a grace period in progress.
108 No grace period, no CPU stall warnings.
136 	This kernel configuration parameter defines the period of time
137 	that RCU will wait from the beginning of a grace period until it
138 	issues an RCU CPU stall warning.  This time period is normally
184 	task stalling the current RCU-tasks grace period.
209 interrupts during the current stalled grace period.
222 last noted the beginning of a grace period, which might be the current
223 (stalled) grace period, or it might be some earlier grace period (for
225 time period.  The number after the "/" is the number that have executed
233 detection passes that the grace-period kthread has made across this
235 period.
239 period (in this case 2603), the grace-period sequence number (7075), and
254 If the grace period ends just as the stall warning starts printing,
262 on how the stall warning and the grace-period initialization happen to
268 grace period has nevertheless failed to end, the stall-warning splat
274 since the grace-period kthread ran.  The "jiffies_till_next_fqs"
280 If the relevant grace-period kthread has been unable to run prior to
286 Starving the grace-period kthreads of CPU time can of course result
289 grace-period sequence number, the "f" precedes the ->gp_flags command
290 to the grace-period kthread, the "RCU_GP_WAIT_FQS" indicates that the
292 task_struct ->state field, and the "cpu" indicates that the grace-period
309 If an expedited grace period detects a stall, it will place a message
316 is online (otherwise the first period would instead have been "O"),
317 that the CPU was online at the beginning of the expedited grace period
318 (otherwise the second period would have instead been "o"), and that
320 period would instead have been "N").  The number before the "jiffies"
321 indicates that the expedited grace period has been going on for 21,119
323 grace-period sequence counter is 73.  The fact that this last value is
324 odd indicates that an expedited grace period is in flight.  The number
327 current expedited grace period.  If the tree had more than one level,