Linus Torvalds 3ba7dfb8da RCU pull request for v6.15
This pull request contains the following branches:
 
 docs.2025.02.04a:
  - Add broken-timing possibility to stallwarn.rst.
  - Improve discussion of this_cpu_ptr(), add raw_cpu_ptr().
  - Document self-propagating callbacks.
  - Point call_srcu() to call_rcu() for detailed memory ordering.
  - Add CONFIG_RCU_LAZY delays to call_rcu() kernel-doc header.
  - Clarify RCU_LAZY and RCU_LAZY_DEFAULT_OFF help text.
  - Remove references to old grace-period-wait primitives.
 
 srcu.2025.02.05a:
  - Introduce srcu_read_{un,}lock_fast(), which is similar to
    srcu_read_{un,}lock_lite(): avoid smp_mb()s in lock and unlock at the
    cost of calling synchronize_rcu() in synchronize_srcu(). Moreover, by
    returning the percpu offset of the counter at srcu_read_lock_fast()
    time, srcu_read_unlock_fast() can save extra pointer dereferencing,
    which makes it faster than srcu_read_{un,}lock_lite().
    srcu_read_{un,}lock_fast() are intended to replace
    rcu_read_{un,}lock_trace() if possible.
 
 torture.2025.02.05a:
  - Add get_torture_init_jiffies() to return the start time of the test.
  - Add a test_boost_holdoff module parameter to allow delaying boosting
    tests when building rcutorture as built-in.
  - Add grace period sequence number logging at the beginning and end of
    failure/close-call results.
  - Switch to hexadecimal for the expedited grace period sequence number
    in the rcu_exp_grace_period trace point.
  - Make cur_ops->format_gp_seqs take buffer length.
  - Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool.
  - Complain when invalid SRCU reader_flavor is specified.
  - Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing, which forces SRCU
    uses atomics even when percpu ops are NMI safe, and use the Kconfig
    for SRCU lockdep testing.
 
 misc.2025.03.04a:
  - Split rcu_report_exp_cpu_mult() mask parameter and use for tracing.
  - Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes().
  - Fix get_state_synchronize_rcu_full() GP-start detection.
  - Move RCU Tasks self-tests to core_initcall().
  - Print segment lengths in show_rcu_nocb_gp_state().
  - Make RCU watch ct_kernel_exit_state() warning.
  - Flush console log from kernel_power_off().
  - rcutorture: Allow a negative value for nfakewriters.
  - rcu: Update TREE05.boot to test normal synchronize_rcu().
  - rcu: Use _full() API to debug synchronize_rcu().
 
 lazypreempt.2025.03.04a: Make RCU handle PREEMPT_LAZY better:
  - Fix header guard for rcu_all_qs().
  - rcu: Rename PREEMPT_AUTO to PREEMPT_LAZY.
  - Update __cond_resched comment about RCU quiescent states.
  - Handle unstable rdp in rcu_read_unlock_strict().
  - Handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y.
  - osnoise: Provide quiescent states.
  - Adjust rcutorture with possible PREEMPT_RCU=n && PREEMPT_COUNT=y
    combination.
  - Limit PREEMPT_RCU configurations.
  - Make rcutorture senario TREE07 and senario TREE10 use PREEMPT_LAZY=y.
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Merge tag 'rcu-next-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Boqun Feng:
 "Documentation:
   - Add broken-timing possibility to stallwarn.rst
   - Improve discussion of this_cpu_ptr(), add raw_cpu_ptr()
   - Document self-propagating callbacks
   - Point call_srcu() to call_rcu() for detailed memory ordering
   - Add CONFIG_RCU_LAZY delays to call_rcu() kernel-doc header
   - Clarify RCU_LAZY and RCU_LAZY_DEFAULT_OFF help text
   - Remove references to old grace-period-wait primitives

  srcu:
   - Introduce srcu_read_{un,}lock_fast(), which is similar to
     srcu_read_{un,}lock_lite(): avoid smp_mb()s in lock and unlock
     at the cost of calling synchronize_rcu() in synchronize_srcu()

     Moreover, by returning the percpu offset of the counter at
     srcu_read_lock_fast() time, srcu_read_unlock_fast() can avoid
     extra pointer dereferencing, which makes it faster than
     srcu_read_{un,}lock_lite()

     srcu_read_{un,}lock_fast() are intended to replace
     rcu_read_{un,}lock_trace() if possible

  RCU torture:
   - Add get_torture_init_jiffies() to return the start time of the test
   - Add a test_boost_holdoff module parameter to allow delaying
     boosting tests when building rcutorture as built-in
   - Add grace period sequence number logging at the beginning and end
     of failure/close-call results
   - Switch to hexadecimal for the expedited grace period sequence
     number in the rcu_exp_grace_period trace point
   - Make cur_ops->format_gp_seqs take buffer length
   - Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
   - Complain when invalid SRCU reader_flavor is specified
   - Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing, which forces SRCU
     uses atomics even when percpu ops are NMI safe, and use the Kconfig
     for SRCU lockdep testing

  Misc:
   - Split rcu_report_exp_cpu_mult() mask parameter and use for tracing
   - Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes()
   - Fix get_state_synchronize_rcu_full() GP-start detection
   - Move RCU Tasks self-tests to core_initcall()
   - Print segment lengths in show_rcu_nocb_gp_state()
   - Make RCU watch ct_kernel_exit_state() warning
   - Flush console log from kernel_power_off()
   - rcutorture: Allow a negative value for nfakewriters
   - rcu: Update TREE05.boot to test normal synchronize_rcu()
   - rcu: Use _full() API to debug synchronize_rcu()

  Make RCU handle PREEMPT_LAZY better:
   - Fix header guard for rcu_all_qs()
   - rcu: Rename PREEMPT_AUTO to PREEMPT_LAZY
   - Update __cond_resched comment about RCU quiescent states
   - Handle unstable rdp in rcu_read_unlock_strict()
   - Handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y
   - osnoise: Provide quiescent states
   - Adjust rcutorture with possible PREEMPT_RCU=n && PREEMPT_COUNT=y
     combination
   - Limit PREEMPT_RCU configurations
   - Make rcutorture senario TREE07 and senario TREE10 use
     PREEMPT_LAZY=y"

* tag 'rcu-next-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (59 commits)
  rcutorture: Make scenario TREE07 build CONFIG_PREEMPT_LAZY=y
  rcutorture: Make scenario TREE10 build CONFIG_PREEMPT_LAZY=y
  rcu: limit PREEMPT_RCU configurations
  rcutorture: Update ->extendables check for lazy preemption
  rcutorture: Update rcutorture_one_extend_check() for lazy preemption
  osnoise: provide quiescent states
  rcu: Use _full() API to debug synchronize_rcu()
  rcu: Update TREE05.boot to test normal synchronize_rcu()
  rcutorture: Allow a negative value for nfakewriters
  Flush console log from kernel_power_off()
  context_tracking: Make RCU watch ct_kernel_exit_state() warning
  rcu/nocb: Print segment lengths in show_rcu_nocb_gp_state()
  rcu-tasks: Move RCU Tasks self-tests to core_initcall()
  rcu: Fix get_state_synchronize_rcu_full() GP-start detection
  torture: Make SRCU lockdep testing use srcu_read_lock_nmisafe()
  srcu: Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing
  rcutorture: Complain when invalid SRCU reader_flavor is specified
  rcutorture: Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
  rcutorture: Make cur_ops->format_gp_seqs take buffer length
  rcutorture: Add ftrace-compatible timestamp to GP# failure/close-call output
  ...
2025-03-24 19:41:37 -07:00
..
2025-03-24 19:41:37 -07:00
2025-03-24 19:41:37 -07:00