kernel_optimize_test/kernel/rcu
Paul E. McKenney 728f23e53c rcu: Invoke rcu_spawn_core_kthreads() from rcu_spawn_gp_kthread()
[ Upstream commit 8e4b1d2bc198e34b48fc7cc3a3c5a2fcb269e271 ]

Currently, rcu_spawn_core_kthreads() is invoked via an early_initcall(),
which works, except that rcu_spawn_gp_kthread() is also invoked via an
early_initcall() and rcu_spawn_core_kthreads() relies on adjustments to
kthread_prio that are carried out by rcu_spawn_gp_kthread().  There is
no guaranttee of ordering among early_initcall() handlers, and thus no
guarantee that kthread_prio will be properly checked and range-limited
at the time that rcu_spawn_core_kthreads() needs it.

In most cases, this bug is harmless.  After all, the only reason that
rcu_spawn_gp_kthread() adjusts the value of kthread_prio is if the user
specified a nonsensical value for this boot parameter, which experience
indicates is rare.

Nevertheless, a bug is a bug.  This commit therefore causes the
rcu_spawn_core_kthreads() function to be invoked directly from
rcu_spawn_gp_kthread() after any needed adjustments to kthread_prio have
been carried out.

Fixes: 48d07c04b4 ("rcu: Enable elimination of Tree-RCU softirq processing")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:33 +02:00
..
Kconfig rcu: Reduce leaf fanout for strict RCU grace periods 2020-08-24 18:40:23 -07:00
Kconfig.debug Merge branch 'strictgp.2020.08.24a' into HEAD 2020-09-03 09:47:42 -07:00
Makefile rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcu_segcblist.c rcu/segcblist: Prevent useless GP start if no CBs to accelerate 2020-09-03 09:39:59 -07:00
rcu_segcblist.h
rcu.h treewide: Make all debug_obj_descriptors const 2020-09-24 21:56:25 +02:00
rcuscale.c rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcutorture.c rcutorture: Allow pointer leaks to test diagnostic code 2020-08-24 18:45:36 -07:00
refscale.c refperf: Avoid null pointer dereference when buf fails to allocate 2020-08-24 18:45:35 -07:00
srcutiny.c
srcutree.c srcu: Remove KCSAN stubs 2020-08-24 18:36:03 -07:00
sync.c
tasks.h rcu-tasks: Move RCU-tasks initialization to before early_initcall() 2021-01-19 18:27:28 +01:00
tiny.c rcu: Rename *_kfree_callback/*_kfree_rcu_offset/kfree_call_* 2020-06-29 11:59:25 -07:00
tree_exp.h rcu: Initialize at declaration time in rcu_exp_handler() 2020-08-24 18:36:03 -07:00
tree_plugin.h rcu/nocb: Perform deferred wake up before last idle's need_resched() check 2021-03-04 11:38:35 +01:00
tree_stall.h rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled 2020-11-10 17:10:38 -08:00
tree.c rcu: Invoke rcu_spawn_core_kthreads() from rcu_spawn_gp_kthread() 2021-07-14 16:56:33 +02:00
tree.h Merge branch 'strictgp.2020.08.24a' into HEAD 2020-09-03 09:47:42 -07:00
update.c Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00