linux/kernel/locking
Linus Torvalds 8cc01d43f8 RCU pull request for v6.3
This pull request contains the following branches:
 
 doc.2023.01.05a: Documentation updates.
 
 fixes.2023.01.23a: Miscellaneous fixes, perhaps most notably:
 
 o	Throttling callback invocation based on the number of callbacks
 	that are now ready to invoke instead of on the total number
 	of callbacks.
 
 o	Several patches that suppress false-positive boot-time
 	diagnostics, for example, due to lockdep not yet being
 	initialized.
 
 o	Make expedited RCU CPU stall warnings dump stacks of any tasks
 	that are blocking the stalled grace period.  (Normal RCU CPU
 	stall warnings have doen this for mnay years.)
 
 o	Lazy-callback fixes to avoid delays during boot, suspend, and
 	resume.  (Note that lazy callbacks must be explicitly enabled,
 	so this should not (yet) affect production use cases.)
 
 kvfree.2023.01.03a: Cause kfree_rcu() and friends to take advantage of
 	polled grace periods, thus reducing memory footprint by almost
 	two orders of magnitude, admittedly on a microbenchmark.
 	This series also begins the transition from kfree_rcu(p) to
 	kfree_rcu_mightsleep(p).  This transition was motivated by bugs
 	where kfree_rcu(p), which can block, was typed instead of the
 	intended kfree_rcu(p, rh).
 
 srcu.2023.01.03a: SRCU updates, perhaps most notably fixing a bug that
 	causes SRCU to fail when booted on a system with a non-zero boot
 	CPU.  This surprising situation actually happens for kdump kernels
 	on the powerpc architecture.  It also adds an srcu_down_read()
 	and srcu_up_read(), which act like srcu_read_lock() and
 	srcu_read_unlock(), but allow an SRCU read-side critical section
 	to be handed off from one task to another.
 
 srcu-always.2023.02.02a: Cleans up the now-useless SRCU Kconfig option.
 	There are a few more commits that are not yet acked or pulled
 	into maintainer trees, and these will be in a pull request for
 	a later merge window.
 
 tasks.2023.01.03a: RCU-tasks updates, perhaps most notably these fixes:
 
 o	A strange interaction between PID-namespace unshare and the
 	RCU-tasks grace period that results in a low-probability but
 	very real hang.
 
 o	A race between an RCU tasks rude grace period on a single-CPU
 	system and CPU-hotplug addition of the second CPU that can result
 	in a too-short grace period.
 
 o	A race between shrinking RCU tasks down to a single callback list
 	and queuing a new callback to some other CPU, but where that
 	queuing is delayed for more than an RCU grace period.  This can
 	result in that callback being stranded on the non-boot CPU.
 
 torture.2023.01.05a: Torture-test updates and fixes.
 
 torturescript.2023.01.03a: Torture-test scripting updates and fixes.
 
 stall.2023.01.09a: Provide additional RCU CPU stall-warning information
 	in kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y, and
 	restore the full five-minute timeout limit for expedited RCU
 	CPU stall warnings.
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Merge tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Documentation updates

 - Miscellaneous fixes, perhaps most notably:

      - Throttling callback invocation based on the number of callbacks
        that are now ready to invoke instead of on the total number of
        callbacks

      - Several patches that suppress false-positive boot-time
        diagnostics, for example, due to lockdep not yet being
        initialized

      - Make expedited RCU CPU stall warnings dump stacks of any tasks
        that are blocking the stalled grace period. (Normal RCU CPU
        stall warnings have done this for many years)

      - Lazy-callback fixes to avoid delays during boot, suspend, and
        resume. (Note that lazy callbacks must be explicitly enabled, so
        this should not (yet) affect production use cases)

 - Make kfree_rcu() and friends take advantage of polled grace periods,
   thus reducing memory footprint by almost two orders of magnitude,
   admittedly on a microbenchmark

   This also begins the transition from kfree_rcu(p) to
   kfree_rcu_mightsleep(p). This transition was motivated by bugs where
   kfree_rcu(p), which can block, was typed instead of the intended
   kfree_rcu(p, rh)

 - SRCU updates, perhaps most notably fixing a bug that causes SRCU to
   fail when booted on a system with a non-zero boot CPU. This
   surprising situation actually happens for kdump kernels on the
   powerpc architecture

   This also adds an srcu_down_read() and srcu_up_read(), which act like
   srcu_read_lock() and srcu_read_unlock(), but allow an SRCU read-side
   critical section to be handed off from one task to another

 - Clean up the now-useless SRCU Kconfig option

   There are a few more commits that are not yet acked or pulled into
   maintainer trees, and these will be in a pull request for a later
   merge window

 - RCU-tasks updates, perhaps most notably these fixes:

      - A strange interaction between PID-namespace unshare and the
        RCU-tasks grace period that results in a low-probability but
        very real hang

      - A race between an RCU tasks rude grace period on a single-CPU
        system and CPU-hotplug addition of the second CPU that can
        result in a too-short grace period

      - A race between shrinking RCU tasks down to a single callback
        list and queuing a new callback to some other CPU, but where
        that queuing is delayed for more than an RCU grace period. This
        can result in that callback being stranded on the non-boot CPU

 - Torture-test updates and fixes

 - Torture-test scripting updates and fixes

 - Provide additional RCU CPU stall-warning information in kernels built
   with CONFIG_RCU_CPU_STALL_CPUTIME=y, and restore the full five-minute
   timeout limit for expedited RCU CPU stall warnings

* tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits)
  rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
  kernel/notifier: Remove CONFIG_SRCU
  init: Remove "select SRCU"
  fs/quota: Remove "select SRCU"
  fs/notify: Remove "select SRCU"
  fs/btrfs: Remove "select SRCU"
  fs: Remove CONFIG_SRCU
  drivers/pci/controller: Remove "select SRCU"
  drivers/net: Remove "select SRCU"
  drivers/md: Remove "select SRCU"
  drivers/hwtracing/stm: Remove "select SRCU"
  drivers/dax: Remove "select SRCU"
  drivers/base: Remove CONFIG_SRCU
  rcu: Disable laziness if lazy-tracking says so
  rcu: Track laziness during boot and suspend
  rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
  rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
  rcu: Align the output of RCU CPU stall warning messages
  rcu: Add RCU stall diagnosis information
  sched: Add helper nr_context_switches_cpu()
  ...
2023-02-21 10:45:51 -08:00
..
irqflag-debug.c lockdep: Noinstr annotate warn_bogus_irq_restore() 2021-02-10 14:44:39 +01:00
lock_events_list.h locking/rwsem: Remove reader optimistic spinning 2020-12-09 17:08:48 +01:00
lock_events.c locking/lock_events: Don't show pvqspinlock events on bare metal 2019-04-10 10:56:05 +02:00
lock_events.h locking/lock_events: Use raw_cpu_{add,inc}() for stats 2019-06-03 12:32:56 +02:00
lockdep_internals.h locking/lockdep: Iterate lock_classes directly when reading lockdep files 2022-02-16 15:57:58 +01:00
lockdep_proc.c locking/lockdep: Iterate lock_classes directly when reading lockdep files 2022-02-16 15:57:58 +01:00
lockdep_states.h locking/lockdep: Rework FS_RECLAIM annotation 2017-08-10 12:29:03 +02:00
lockdep.c cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG 2023-01-31 15:01:45 +01:00
locktorture.c locktorture: Make the rt_boost factor a tunable 2023-01-05 12:10:35 -08:00
Makefile lockdep: allow instrumenting lockdep.c with KMSAN 2022-12-11 18:12:11 -08:00
mcs_spinlock.h locking: Fix typos in comments 2021-03-22 02:45:52 +01:00
mutex-debug.c locking/ww_mutex: Gather mutex_waiter initialization 2021-08-17 19:04:41 +02:00
mutex.c locking/mutex: Make contention tracepoints more consistent wrt adaptive spinning 2022-04-05 10:24:36 +02:00
mutex.h locking/mutex: Move the 'struct mutex_waiter' definition from <linux/mutex.h> to the internal header 2021-08-17 18:24:31 +02:00
osq_lock.c locking: Fix typos in comments 2021-03-22 02:45:52 +01:00
percpu-rwsem.c locking/percpu-rwsem: Add percpu_is_write_locked() and percpu_is_read_locked() 2022-08-30 10:56:23 +02:00
qrwlock.c locking: Add __lockfunc to slow path functions 2022-08-19 19:47:51 +02:00
qspinlock_paravirt.h locking: Add __lockfunc to slow path functions 2022-08-19 19:47:51 +02:00
qspinlock_stat.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
qspinlock.c locking/qspinlock: Micro-optimize pending state waiting for unlock 2023-01-05 11:01:50 +01:00
rtmutex_api.c rtmutex: Add acquire semantics for rtmutex lock acquisition slow path 2022-12-12 19:55:56 +01:00
rtmutex_common.h locking/rtmutex: Dont dereference waiter lockless 2021-08-25 15:42:32 +02:00
rtmutex.c rtmutex: Ensure that the top waiter is always woken up 2023-02-06 14:49:13 +01:00
rwbase_rt.c locking: Apply contention tracepoints in the slow path 2022-04-05 10:24:35 +02:00
rwsem.c locking/rwsem: Disable preemption in all down_write*() and up_write() code paths 2023-01-26 11:46:46 +01:00
semaphore.c locking: Add __sched to semaphore functions 2022-09-15 16:14:03 +02:00
spinlock_debug.c locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
spinlock_rt.c locking/rwlocks: introduce write_lock_nested 2022-01-22 08:33:37 +02:00
spinlock.c locking/spinlocks: Mark spinlocks noinline when inline spinlocks are disabled 2022-08-04 11:05:43 +02:00
test-ww_mutex.c treewide: use get_random_u32_below() instead of deprecated function 2022-11-18 02:15:15 +01:00
ww_mutex.h locking/ww_mutex: Add rt_mutex based lock type and accessors 2021-08-17 19:05:11 +02:00
ww_rt_mutex.c kernel/locking: Use a pointer in ww_mutex_trylock(). 2021-11-17 14:48:49 +01:00