linux/kernel/rcu
Paul E. McKenney 5b14557b07 rcu: Avoid tick_dep_set_cpu() misordering
In the current code, rcu_nmi_enter_common() might decide to turn on
the tick using tick_dep_set_cpu(), but be delayed just before doing so.
Then the grace-period kthread might notice that the CPU in question had
in fact gone through a quiescent state, thus turning off the tick using
tick_dep_clear_cpu().  The later invocation of tick_dep_set_cpu() would
then incorrectly leave the tick on.

This commit therefore enlists the aid of the leaf rcu_node structure's
->lock to ensure that decisions to enable or disable the tick are
carried out before they can be reversed.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
..
Kconfig rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
Kconfig.debug rcu: Add support for consolidated-RCU reader checking 2019-08-09 11:00:35 -07:00
Makefile rcu: Make PREEMPT_RCU be a modifier to TREE_RCU 2019-12-09 12:37:51 -08:00
rcu_segcblist.c rcu: Several rcu_segcblist functions can be static 2019-10-30 08:33:22 -07:00
rcu_segcblist.h rcu/nocb: Add bypass callback queueing 2019-08-13 14:37:32 -07:00
rcu.h rcu: Make PREEMPT_RCU be a modifier to TREE_RCU 2019-12-09 12:37:51 -08:00
rcuperf.c rcu: Remove unused variable rcu_perf_writer_state 2019-10-05 11:49:36 -07:00
rcutorture.c rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
srcutiny.c rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
srcutree.c srcu: Avoid srcutorture security-based pointer obfuscation 2019-08-01 14:05:51 -07:00
sync.c rcu/sync: Simplify the state machine 2019-05-28 09:05:23 -07:00
tiny.c rcu: rcu_qs -- Use raise_softirq_irqoff to not save irqs twice 2019-03-26 14:37:49 -07:00
tree_exp.h rcu: Provide wrappers for uses of ->rcu_read_lock_nesting 2020-01-24 10:27:33 -08:00
tree_plugin.h rcu: Provide wrappers for uses of ->rcu_read_lock_nesting 2020-01-24 10:27:33 -08:00
tree_stall.h rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU 2020-01-24 10:26:28 -08:00
tree.c rcu: Avoid tick_dep_set_cpu() misordering 2020-01-24 10:27:33 -08:00
tree.h rcu: Force tick on for nohz_full CPUs not reaching quiescent states 2019-10-28 07:02:21 -07:00
update.c rcu: Make PREEMPT_RCU be a modifier to TREE_RCU 2019-12-09 12:37:51 -08:00