linux/kernel/rcu
Paul E. McKenney f25390033f rcu-tasks: Print pre-stall-warning informational messages
RCU-tasks stall-warning messages are printed after the grace period is ten
minutes old.  Unfortunately, most of us will have rebooted the system in
response to an apparently-hung command long before the ten minutes is up,
and will thus see what looks to be a silent hang.

This commit therefore adds pr_info() messages that are printed earlier.
These should avoid being classified as errors, but should give impatient
users a hint.  These are controlled by new rcupdate.rcu_task_stall_info
and rcupdate.rcu_task_stall_info_mult kernel-boot parameters.  The former
defines the initial delay in jiffies (defaulting to 10 seconds) and the
latter defines the multiplier (defaulting to 3).  Thus, by default, the
first message will appear 10 seconds into the RCU-tasks grace period,
the second 40 seconds in, and the third 160 seconds in.  There would be
a fourth at 640 seconds in, but the stall warning message appears 600
seconds in, and once a stall warning is printed for a given grace period,
no further informational messages are printed.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-11 17:06:42 -07:00
..
Kconfig Merge branches 'doc.2021.11.30c', 'exp.2021.12.07a', 'fastnohz.2021.11.30c', 'fixes.2021.11.30c', 'nocb.2021.12.09a', 'nolibc.2021.11.30c', 'tasks.2021.12.09a', 'torture.2021.12.07a' and 'torturescript.2021.11.30c' into HEAD 2021-12-09 11:38:09 -08:00
Kconfig.debug rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs 2021-05-10 16:22:54 -07:00
Makefile rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcu_segcblist.c rcu/nocb: Invoke rcu_core() at the start of deoffloading 2021-12-07 16:24:44 -08:00
rcu_segcblist.h rcu: Mark writes to the rcu_segcblist structure's ->flags field 2022-02-14 10:36:58 -08:00
rcu.h Merge branches 'bitmaprange.2021.05.10c', 'doc.2021.05.10c', 'fixes.2021.05.13a', 'kvfree_rcu.2021.05.10c', 'mmdumpobj.2021.05.10c', 'nocb.2021.05.12a', 'srcu.2021.05.12a', 'tasks.2021.05.18a' and 'torture.2021.05.10c' into HEAD 2021-05-18 10:56:19 -07:00
rcuscale.c rcuscale: Always log error message 2021-12-07 16:36:17 -08:00
rcutorture.c Merge branches 'exp.2022.02.24a', 'fixes.2022.02.14a', 'rcu_barrier.2022.02.08a', 'rcu-tasks.2022.02.08a', 'rt.2022.02.01b', 'torture.2022.02.01b' and 'torturescript.2022.02.08a' into HEAD 2022-02-24 09:38:46 -08:00
refscale.c refscale: Add missing '\n' to flush message 2021-12-07 16:36:12 -08:00
srcutiny.c srcu: Prevent redundant __srcu_read_unlock() wakeup 2021-11-30 17:28:16 -08:00
srcutree.c Merge branches 'bitmaprange.2021.05.10c', 'doc.2021.05.10c', 'fixes.2021.05.13a', 'kvfree_rcu.2021.05.10c', 'mmdumpobj.2021.05.10c', 'nocb.2021.05.12a', 'srcu.2021.05.12a', 'tasks.2021.05.18a' and 'torture.2021.05.10c' into HEAD 2021-05-18 10:56:19 -07:00
sync.c rcu: Fix various typos in comments 2021-05-12 12:11:05 -07:00
tasks.h rcu-tasks: Print pre-stall-warning informational messages 2022-04-11 17:06:42 -07:00
tiny.c srcu: Initialize SRCU after timers 2021-05-10 16:03:35 -07:00
tree_exp.h rcu: Mark ->expmask access in synchronize_rcu_expedited_wait() 2022-02-01 17:05:10 -08:00
tree_nocb.h Merge branches 'exp.2022.02.24a', 'fixes.2022.02.14a', 'rcu_barrier.2022.02.08a', 'rcu-tasks.2022.02.08a', 'rt.2022.02.01b', 'torture.2022.02.01b' and 'torturescript.2022.02.08a' into HEAD 2022-02-24 09:38:46 -08:00
tree_plugin.h Changes in this cycle were: 2022-03-22 14:39:12 -07:00
tree_stall.h rcu: Add per-CPU rcuc task dumps to RCU CPU stall warnings 2022-02-01 17:22:17 -08:00
tree.c RCU pull request for v5.18 2022-03-21 14:00:56 -07:00
tree.h Merge branches 'exp.2022.02.24a', 'fixes.2022.02.14a', 'rcu_barrier.2022.02.08a', 'rcu-tasks.2022.02.08a', 'rt.2022.02.01b', 'torture.2022.02.01b' and 'torturescript.2022.02.08a' into HEAD 2022-02-24 09:38:46 -08:00
update.c rcu: Uninline multi-use function: finish_rcuwait() 2022-02-14 10:36:58 -08:00