linux-stable/kernel/rcu
Frederic Weisbecker 483d5bf231 rcu/nocb: Use kthread parking instead of ad-hoc implementation
Upon NOCB deoffloading, the rcuo kthread must be forced to sleep
until the corresponding rdp is ever offloaded again. The deoffloader
clears the SEGCBLIST_OFFLOADED flag, wakes up the rcuo kthread which
then notices that change and clears in turn its SEGCBLIST_KTHREAD_CB
flag before going to sleep, until it ever sees the SEGCBLIST_OFFLOADED
flag again, should a re-offloading happen.

Upon NOCB offloading, the rcuo kthread must be forced to wake up and
handle callbacks until the corresponding rdp is ever deoffloaded again.
The offloader sets the SEGCBLIST_OFFLOADED flag, wakes up the rcuo
kthread which then notices that change and sets in turn its
SEGCBLIST_KTHREAD_CB flag before going to check callbacks, until it
ever sees the SEGCBLIST_OFFLOADED flag cleared again, should a
de-offloading happen again.

This is all a crude ad-hoc and error-prone kthread (un-)parking
re-implementation.

Consolidate the behaviour with the appropriate API instead.

[ paulmck: Apply Qiang Zhang feedback provided in Link: below. ]
Link: https://lore.kernel.org/all/20240509074046.15629-1-qiang.zhang1211@gmail.com/

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-06-03 17:26:26 -07:00
..
Kconfig rcu: Create NEED_TASKS_RCU to factor out enablement logic 2024-04-15 11:29:48 +02:00
Kconfig.debug rcu: Restrict access to RCU CPU stall notifiers 2023-12-12 02:31:22 +05:30
Makefile rcuperf: Change rcuperf to rcuscale 2020-08-24 18:39:24 -07:00
rcu_segcblist.c rcu: Use rcu_segcblist_segempty() instead of open coding it 2023-10-04 17:33:18 +02:00
rcu_segcblist.h rcu: Throttle callback invocation based on number of ready callbacks 2023-01-03 17:28:34 -08:00
rcu.h rcutorture: Make rcutorture support print rcu-tasks gp state 2024-04-16 11:16:35 +02:00
rcuscale.c rcu: Rename jiffies_till_flush to jiffies_lazy_flush 2024-02-14 08:00:57 -08:00
rcutorture.c rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test 2024-04-16 11:16:36 +02:00
refscale.c refscale: Print out additional module parameters 2023-09-11 23:02:18 +02:00
srcutiny.c srcu: Make Tiny SRCU explicitly disable preemption 2024-04-15 11:29:48 +02:00
srcutree.c rcutorture: Make rcutorture support print rcu-tasks gp state 2024-04-16 11:16:35 +02:00
sync.c rcu: Mark writes to rcu_sync ->gp_count field 2024-04-15 16:28:46 +02:00
tasks.h Merge branches 'fixes.2024.04.15a', 'misc.2024.04.12a', 'rcu-sync-normal-improve.2024.04.15a', 'rcu-tasks.2024.04.15a' and 'rcutorture.2024.04.15a' into rcu-merge.2024.04.15a 2024-05-01 13:04:02 +02:00
tiny.c rcu: Make Tiny RCU explicitly disable preemption 2024-04-15 11:29:48 +02:00
tree_exp.h rcu: Reduce synchronize_rcu() latency 2024-04-15 19:47:49 +02:00
tree_nocb.h rcu/nocb: Use kthread parking instead of ad-hoc implementation 2024-06-03 17:26:26 -07:00
tree_plugin.h rcu/nocb: Use kthread parking instead of ad-hoc implementation 2024-06-03 17:26:26 -07:00
tree_stall.h rcu: Fix buffer overflow in print_cpu_stall_info() 2024-04-15 19:43:50 +02:00
tree.c Merge branches 'fixes.2024.04.15a', 'misc.2024.04.12a', 'rcu-sync-normal-improve.2024.04.15a', 'rcu-tasks.2024.04.15a' and 'rcutorture.2024.04.15a' into rcu-merge.2024.04.15a 2024-05-01 13:04:02 +02:00
tree.h Merge branches 'fixes.2024.04.15a', 'misc.2024.04.12a', 'rcu-sync-normal-improve.2024.04.15a', 'rcu-tasks.2024.04.15a' and 'rcutorture.2024.04.15a' into rcu-merge.2024.04.15a 2024-05-01 13:04:02 +02:00
update.c rcu-tasks: Make Tasks RCU wait idly for grace-period delays 2024-04-09 15:11:49 +02:00