Hi Linus, Please pull this for the RCU changes of v6.9: The following changes since commit 41bccc98fb7931d63d03f326a746ac4d429c1dd3: Linux 6.8-rc2 (2024-01-28 17:01:12 -0800) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux.git tags/rcu.next.v6.9 for you to fetch changes up to 3add00be5fe5810d7aa5ec3af8b6a245ef33144b: Merge branches 'rcu-doc.2024.02.14a', 'rcu-nocb.2024.02.14a', 'rcu-exp.2024.02.14a', 'rcu-tasks.2024.02.26a' and 'rcu-misc.2024.02.14a' into rcu.2024.02.26a (2024-02-26 17:37:25 -0800) Two merge conflicts were detected by linux-next: * https://lore.kernel.org/lkml/20240226135745.12ac854d@xxxxxxxxxxxxxxxx/ * https://lore.kernel.org/lkml/20240227125522.2bdbe6be@xxxxxxxxxxxxxxxx/ These conflict resolutions from linux-next look good to me, plus I made my own resolutions at branch merge/rcu.2024.02.27a for your reference. Some highlights of the changes: * Eliminates deadlocks involving do_exit() and RCU tasks, by Paul: Instead of SRCU read side critical sections, now a percpu list is used in do_exit() for scaning yet-to-exit tasks. * Fixes a deadlock due to the dependency between workqueue and RCU expedited grace period, reported by Anna-Maria Behnsen and Thomas Gleixner and fixed by Frederic: Now RCU expedited always uses its own kthread worker instead of a workqueue. Regards, Boqun ---------------------------------------------------------------- RCU pull request for v6.9 This pull request contains the following branches: rcu-doc.2024.02.14a: Documentation updates. rcu-nocb.2024.02.14a: RCU NOCB updates, code cleanups, unnecessary barrier removals and minor bug fixes. rcu-exp.2024.02.14a: RCU exp, fixing a circular dependency between workqueue and RCU expedited callback handling. rcu-tasks.2024.02.26a: RCU tasks, avoiding deadlocks in do_exit() when calling synchronize_rcu_task() with a mutex hold, maintaining real-time response in rcu_tasks_postscan() and a minor fix for tasks trace quiescence check. rcu-misc.2024.02.14a: Misc updates, comments and readibility improvement, boot time parameter for lazy RCU and rcutorture improvement. ---------------------------------------------------------------- Boqun Feng (1): Merge branches 'rcu-doc.2024.02.14a', 'rcu-nocb.2024.02.14a', 'rcu-exp.2024.02.14a', 'rcu-tasks.2024.02.26a' and 'rcu-misc.2024.02.14a' into rcu.2024.02.26a Frederic Weisbecker (13): rcu/nocb: Remove needless LOAD-ACQUIRE rcu/nocb: Remove needless full barrier after callback advancing rcu/nocb: Make IRQs disablement symmetric rcu/nocb: Re-arrange call_rcu() NOCB specific code rcu/exp: Remove full barrier upon main thread wakeup rcu/exp: Fix RCU expedited parallel grace period kworker allocation failure recovery rcu/exp: Handle RCU expedited grace period kworker allocation failure rcu: s/boost_kthread_mutex/kthread_mutex rcu/exp: Move expedited kthread worker creation functions above rcutree_prepare_cpu() rcu/exp: Make parallel exp gp kworker per rcu node rcu/exp: Handle parallel exp gp kworkers affinity rcu/exp: Remove rcu_par_gp_wq rcu: Rename jiffies_till_flush to jiffies_lazy_flush Joel Fernandes (Google) (1): srcu: Improve comments about acceleration leak Onkarnath (1): rcu/sync: remove un-used rcu_sync_enter_start function Paul E. McKenney (16): doc: Spinlocks are implied RCU readers doc: Make whatisRCU.rst note that spinlocks are RCU readers doc: Make checklist.rst note that spinlocks are implied RCU readers doc: Add CONFIG_RCU_STRICT_GRACE_PERIOD to checklist.rst doc: Add EARLY flag to early-parsed kernel boot parameters context_tracking: Fix kerneldoc headers for __ct_user_{enter,exit}() doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU doc: Update checklist.rst discussion of callback execution rcutorture: Suppress rtort_pipe_count warnings until after stalls rcu-tasks: Repair RCU Tasks Trace quiescence check rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Initialize callback lists at rcu_init() time rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Maintain lists to eliminate RCU-tasks/do_exit() deadlocks rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks rcu-tasks: Maintain real-time response in rcu_tasks_postscan() Qais Yousef (1): rcu: Provide a boot time parameter to control lazy RCU Zqiang (2): rcu/nocb: Fix WARN_ON_ONCE() in the rcu_nocb_bypass_lock() rcu/nocb: Check rdp_gp->nocb_timer in __call_rcu_nocb_wake() Documentation/RCU/checklist.rst | 32 +- Documentation/RCU/rcu_dereference.rst | 5 +- Documentation/RCU/whatisRCU.rst | 19 +- Documentation/admin-guide/kernel-parameters.rst | 1 + Documentation/admin-guide/kernel-parameters.txt | 489 ++++++++++++------------ include/linux/rcu_sync.h | 1 - include/linux/rcupdate.h | 4 +- include/linux/sched.h | 2 + init/init_task.c | 1 + kernel/context_tracking.c | 4 + kernel/fork.c | 1 + kernel/rcu/Kconfig | 13 + kernel/rcu/rcu.h | 19 +- kernel/rcu/rcuscale.c | 6 +- kernel/rcu/rcutorture.c | 13 +- kernel/rcu/srcutree.c | 24 +- kernel/rcu/sync.c | 16 - kernel/rcu/tasks.h | 135 +++++-- kernel/rcu/tiny.c | 1 + kernel/rcu/tree.c | 237 ++++++++---- kernel/rcu/tree.h | 20 +- kernel/rcu/tree_exp.h | 83 +--- kernel/rcu/tree_nocb.h | 69 ++-- kernel/rcu/tree_plugin.h | 52 +-- 24 files changed, 687 insertions(+), 560 deletions(-)
