From: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Architectures for which all deep-idle and entry-exit functions are
marked noinstr, synchronize_rcu_tasks_rude() is not required. However,
disabling synchronize_rcu_tasks_rude() for such architectures require
RCU-tasks to pay attention to idle tasks until they enter the context
where RCU is not watching. In addition, NMI context need to track RCU-tasks
entry/exit for NO_HZ_FULL CPUs. This series adds changes for both of
these requirements.
The series is available in git tree at:
https://git.kernel.org/pub/scm/linux/kernel/git/neeraj.upadhyay/linux-rcu.git/log/?h=rcu.tasks.idle
Changes since v1: https://lore.kernel.org/lkml/20240807163506.434885-1-neeraj.upadhyay@kernel.org/
- Split into multiple patches (Paul)
- Various restructuring updates (Frederic)
- Fix race with early boot code (Frederic)
- Check RCU watching state for idle injection tasks.
- Include patch to turn synchronize_rcu_tasks_rude() into noop
for architectures with CONFIG_ARCH_WANTS_NO_INSTR enabled.
Neeraj Upadhyay (9):
rcu: Change rdp arg to cpu number for
rcu_watching_snap_stopped_since()
rcu: Make some rcu_watching_* functions global
rcu/tasks: Move holdout checks for idle task to a separate function
rcu/tasks: Create rcu_idle_task_is_holdout() definition for !SMP
rcu/tasks: Consider idle tasks not running on CPU as non-holdouts
rcu/tasks: Check RCU watching state for holdout idle tasks
rcu/tasks: Check RCU watching state for holdout idle injection tasks
rcu/tasks: Make RCU-tasks pay attention to idle tasks
context_tracking: Invoke RCU-tasks enter/exit for NMI context
Paul E. McKenney (1):
rcu: Allow short-circuiting of synchronize_rcu_tasks_rude()
.../RCU/Design/Requirements/Requirements.rst | 12 +-
kernel/context_tracking.c | 11 +-
kernel/rcu/rcu.h | 4 +
kernel/rcu/tasks.h | 148 ++++++++++++++----
kernel/rcu/tree.c | 16 +-
kernel/rcu/tree_exp.h | 2 +-
6 files changed, 140 insertions(+), 53 deletions(-)
--
2.40.1