linux_dsm_epyc7002/kernel/rcu
Paul E. McKenney ad7c946b35 rcu: Create RCU-specific workqueues with rescuers
RCU's expedited grace periods can participate in out-of-memory deadlocks
due to all available system_wq kthreads being blocked and there not being
memory available to create more.  This commit prevents such deadlocks
by allocating an RCU-specific workqueue_struct at early boot time, and
providing it with a rescuer to ensure forward progress.  This uses the
shiny new init_rescuer() function provided by Tejun (but indirectly).

This commit also causes SRCU to use this new RCU-specific
workqueue_struct.  Note that SRCU's use of workqueues never blocks them
waiting for readers, so this should be safe from a forward-progress
viewpoint.  Note that this moves SRCU from system_power_efficient_wq
to a normal workqueue.  In the unlikely event that this results in
measurable degradation, a separate power-efficient workqueue will be
creates for SRCU.

Reported-by: Prateek Sood <prsood@codeaurora.org>
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
2018-02-23 15:14:40 -08:00
..
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_segcblist.c rcu/segcblist: Include rcupdate.h 2017-10-19 12:13:36 -07:00
rcu_segcblist.h rcu: Remove unused RCU list functions 2017-07-25 13:04:49 -07:00
rcu.h rcu: Create RCU-specific workqueues with rescuers 2018-02-23 15:14:40 -08:00
rcuperf.c torture: Eliminate torture_runnable and perf_runnable 2017-12-11 09:18:29 -08:00
rcutorture.c torture: Eliminate torture_runnable and perf_runnable 2017-12-11 09:18:29 -08:00
srcutiny.c srcu: Move rcu_scheduler_starting() from Tiny RCU to Tiny SRCU 2017-07-24 16:03:22 -07:00
srcutree.c rcu: Create RCU-specific workqueues with rescuers 2018-02-23 15:14:40 -08:00
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_exp.h rcu: Create RCU-specific workqueues with rescuers 2018-02-23 15:14:40 -08:00
tree_plugin.h rcu: Use wrapper for lockdep asserts 2018-02-20 16:12:26 -08:00
tree.c rcu: Create RCU-specific workqueues with rescuers 2018-02-23 15:14:40 -08:00
tree.h rcu: Remove redundant nxttail index macro define 2018-02-20 16:10:31 -08:00
update.c rcu: Export init_rcu_head() and destroy_rcu_head() to GPL modules 2017-12-07 19:51:49 -05:00