linux-stable/kernel/rcu
Paul E. McKenney 8c42b1f39f rcu: Exclude near-simultaneous RCU CPU stall warnings
There is a two-jiffy delay between the time that a CPU will self-report
an RCU CPU stall warning and the time that some other CPU will report a
warning on behalf of the first CPU.  This has worked well in the past,
but on busy systems, it is possible for the two warnings to overlap,
which makes interpreting them extremely difficult.

This commit therefore uses a cmpxchg-based timing decision that
allows only one report in a given one-minute period (assuming default
stall-warning Kconfig parameters).  This approach will of course fail
if you are seeing minute-long vCPU preemption, but in that case the
overlapping RCU CPU stall warnings are the least of your worries.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-06-26 12:25:56 -07:00
..
Kconfig rcu: Drive TASKS_RCU directly off of PREEMPT 2017-08-17 07:26:04 -07:00
Kconfig.debug rcu: Move RCU debug Kconfig options to kernel/rcu 2017-06-08 18:52:44 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rcu.h Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' and 'torture.2018.05.15a' into HEAD 2018-05-15 10:33:05 -07:00
rcu_segcblist.c rcu: Simplify and inline cpu_needs_another_gp() 2018-05-15 10:30:59 -07:00
rcu_segcblist.h rcu: Simplify and inline cpu_needs_another_gp() 2018-05-15 10:30:59 -07:00
rcuperf.c rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() 2018-05-15 10:27:29 -07:00
rcutorture.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
srcutiny.c srcu: Add cleanup_srcu_struct_quiesced() 2018-05-15 10:27:56 -07:00
srcutree.c srcu: Add cleanup_srcu_struct_quiesced() 2018-05-15 10:27:56 -07:00
sync.c doc: Fix various RCU docbook comment-header problems 2017-10-19 22:26:11 -04:00
tiny.c srcu: Move rcu_scheduler_starting() from Tiny RCU to Tiny SRCU 2017-07-24 16:03:22 -07:00
tree.c rcu: Exclude near-simultaneous RCU CPU stall warnings 2018-06-26 12:25:56 -07:00
tree.h rcu: Add debugging info to assertion 2018-06-26 12:25:55 -07:00
tree_exp.h Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' and 'torture.2018.05.15a' into HEAD 2018-05-15 10:33:05 -07:00
tree_plugin.h rcu: Use the proper lockdep annotation in dump_blkd_tasks() 2018-06-26 12:25:55 -07:00
update.c rcu: Move __rcu_read_lock() and __rcu_read_unlock() to tree_plugin.h 2018-05-15 10:27:41 -07:00