linux/kernel/rcu
Linus Torvalds 8cdf2d1903 RCU pull request for v6.13
SRCU:
 
 	- Introduction of the new SRCU-lite flavour with a new pair of
 	  srcu_read_[un]lock_lite() APIs. In practice the read side using
 	  this flavour becomes lighter by removing a full memory barrier on
 	  LOCK and a full memory barrier on UNLOCK. This comes at the
 	  expense of a higher latency write side with two (in the best case
 	  of a snaphot of unused read-sides) or more RCU grace periods on
 	  the update side which now assumes by itself the whole full
 	  ordering guarantee against the LOCK/UNLOCK counters on both
 	  indexes, along with the accesses performed inside.
 
 	  Uretprobes is a known potential user.
 
 	  Note this doesn't replace the default normal flavour of SRCU which
 	  still behaves the same as usual.
 
 	- Add testing of SRCU-lite through rcutorture and rcuscale
 
 	- Various cleanups on the way.
 
 FIXES:
 
 	- Allow short-circuiting RCU-TASKS-RUDE grace periods on architectures
 	  that have sane noinstr boundaries forbidding tracing on low-level
 	  idle and kernel entry code. RCU-TASKS is enough on such configurations
 	  because it involves an RCU grace period that waits for all idle
 	  tasks to either schedule out voluntarily or enter into RCU
 	  unwatched noinstr code.
 
 	- Allow and test start_poll_synchronize_rcu() with IRQs disabled.
 
 	- Mention rcuog kthreads in relevant documentation and Kconfig help
 
 	- Various fixes and consolidations
 
 RCUTORTURE:
 
 	- Add --no-affinity on tools to leave the affinity setting of guests
 	  up to the user.
 
 	- Add guest_os_delay parameter to rcuscale for better warm-up
 	  control.
 
 	- Fix and improve some rcuscale error handling.
 
 	- Various cleanups and fixes
 
 STALL:
 
 	- Remove dead code
 
 	- Stop dumping tasks if a stalled grace period eventually ended
 	  midway as that only produces confusing output.
 
 	- Optimize detection of stalling CPUs and avoid useless node
 	  locking otherwise.
 
 NOCB:
 
 	- Fix rcu_barrier() hang due to a race against callbacks
 	  deoffloading. This is not yet used, except by rcutorture, and
 	  waits for its promised cpusets interface.
 
 	- Remove leftover function declaration
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEd76+gtGM8MbftQlOhSRUR1COjHcFAmc6gP0ACgkQhSRUR1CO
 jHcHfw/5AWg5wiapwJtLO9KNdtELflTTbT/NhhqwYVReHnOSvtPNwWgo984T3jYJ
 xikE4Ccn5Nu4zJVbTOtmwJ/RP6WWP1I28LgoTCdcz9BB9b+CRLogV/dR5r5uZbhD
 +jqXRAzDhEifR0pcfSK28MkXoh+puXMg4C78f7xtT1Oe3Gr67RLf6xvE59gHJrDg
 QrPStdwhOn2bhmbKcflw1bHYqpypL09P2WHuRLmsJJUMUGIHTohK05lJOkD3hV9g
 HTxOecNmeF/r8NyN8l/ERJgKmwDukIG02xih8UMEtqDEl04IxZFHbCfB6yyIsKDT
 fTFxnRCHnm/PxIKRA5ENvyg/6uArMJ0xuSTZRG4K5v0nx7okR8gbCPmwiwn1m5w3
 +/oppjCmG/gRgyiOytuEGKfaN9q/oJqQgeS7j8WruWj9V68FYUKr6COfQByw0xOc
 H6ftaLGeFHgHxk3nua2wFrfMtQhucYAMGAlVK82yd7Q1EFW47kzleO8w/HSvfrBt
 trX+9HZ77GVVmREJMstnIWRr5mbPtUf8yRZdA5bBrlEYz0A/ToNaFACid0fsaMC2
 Dbo9Q+wDqL2wwOpjZy+MA3k1IVyDdUTuOQmPt57LmFTxUNZ+AQQlJcrhrUqWVvdM
 Nne2EHdqCHADKd7g3i17HtvpTsapz+Qakpzx8UsPqNtfo1DSd5A=
 =MWrw
 -----END PGP SIGNATURE-----

Merge tag 'rcu.release.v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Frederic Weisbecker:
 "SRCU:

   - Introduction of the new SRCU-lite flavour with a new pair of
     srcu_read_[un]lock_lite() APIs. In practice the read side using
     this flavour becomes lighter by removing a full memory barrier on
     LOCK and a full memory barrier on UNLOCK. This comes at the expense
     of a higher latency write side with two (in the best case of a
     snaphot of unused read-sides) or more RCU grace periods on the
     update side which now assumes by itself the whole full ordering
     guarantee against the LOCK/UNLOCK counters on both indexes, along
     with the accesses performed inside.

     Uretprobes is a known potential user.

     Note this doesn't replace the default normal flavour of SRCU which
     still behaves the same as usual.

   - Add testing of SRCU-lite through rcutorture and rcuscale

   - Various cleanups on the way.

  Fixes:

   - Allow short-circuiting RCU-TASKS-RUDE grace periods on
     architectures that have sane noinstr boundaries forbidding tracing
     on low-level idle and kernel entry code. RCU-TASKS is enough on
     such configurations because it involves an RCU grace period that
     waits for all idle tasks to either schedule out voluntarily or
     enter into RCU unwatched noinstr code.

   - Allow and test start_poll_synchronize_rcu() with IRQs disabled.

   - Mention rcuog kthreads in relevant documentation and Kconfig help

   - Various fixes and consolidations

  rcutorture:

   - Add --no-affinity on tools to leave the affinity setting of guests
     up to the user.

   - Add guest_os_delay parameter to rcuscale for better warm-up
     control.

   - Fix and improve some rcuscale error handling.

   - Various cleanups and fixes

  stall:

   - Remove dead code

   - Stop dumping tasks if a stalled grace period eventually ended
     midway as that only produces confusing output.

   - Optimize detection of stalling CPUs and avoid useless node locking
     otherwise.

  NOCB:

   - Fix rcu_barrier() hang due to a race against callbacks
     deoffloading. This is not yet used, except by rcutorture, and waits
     for its promised cpusets interface.

   - Remove leftover function declaration"

* tag 'rcu.release.v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (42 commits)
  rcuscale: Remove redundant WARN_ON_ONCE() splat
  rcuscale: Do a proper cleanup if kfree_scale_init() fails
  srcu: Unconditionally record srcu_read_lock_lite() in ->srcu_reader_flavor
  srcu: Check for srcu_read_lock_lite() across all CPUs
  srcu: Remove smp_mb() from srcu_read_unlock_lite()
  rcutorture: Avoid printing cpu=-1 for no-fault RCU boost failure
  rcuscale: Add guest_os_delay module parameter
  refscale: Correct affinity check
  torture: Add --no-affinity parameter to kvm.sh
  rcu/nocb: Fix missed RCU barrier on deoffloading
  rcu/kvfree: Fix data-race in __mod_timer / kvfree_call_rcu
  rcu/srcutiny: don't return before reenabling preemption
  rcu-tasks: Remove open-coded one-byte cmpxchg() emulation
  doc: Remove kernel-parameters.txt entry for rcutorture.read_exit
  rcutorture: Test start-poll primitives with interrupts disabled
  rcu: Permit start_poll_synchronize_rcu*() with interrupts disabled
  rcu: Allow short-circuiting of synchronize_rcu_tasks_rude()
  doc: Add rcuog kthreads to kernel-per-CPU-kthreads.rst
  rcu: Add rcuog kthreads to RCU_NOCB_CPU help text
  rcu: Use the BITS_PER_LONG macro
  ...
2024-11-19 11:27:07 -08:00
..
Kconfig rcu: Add rcuog kthreads to RCU_NOCB_CPU help text 2024-11-12 21:41:08 +01:00
Kconfig.debug
Makefile
rcu_segcblist.c rcu/nocb: Simplify (de-)offloading state machine 2024-09-09 00:03:55 +05:30
rcu_segcblist.h rcu: Remove unused declaration rcu_segcblist_offload() 2024-10-22 15:36:56 +02:00
rcu.h Merge branches 'context_tracking.15.08.24a', 'csd.lock.15.08.24a', 'nocb.09.09.24a', 'rcutorture.14.08.24a', 'rcustall.09.09.24a', 'srcu.12.08.24a', 'rcu.tasks.14.08.24a', 'rcu_scaling_tests.15.08.24a', 'fixes.12.08.24a' and 'misc.11.08.24a' into next.09.09.24a 2024-09-09 00:09:47 +05:30
rcuscale.c rcuscale: Remove redundant WARN_ON_ONCE() splat 2024-11-15 22:24:41 +01:00
rcutorture.c Merge branches 'rcu/fixes', 'rcu/nocb', 'rcu/torture', 'rcu/stall' and 'rcu/srcu' into rcu/dev 2024-11-15 22:38:53 +01:00
refscale.c Merge branches 'rcu/fixes', 'rcu/nocb', 'rcu/torture', 'rcu/stall' and 'rcu/srcu' into rcu/dev 2024-11-15 22:38:53 +01:00
srcutiny.c rcu/srcutiny: don't return before reenabling preemption 2024-11-12 21:45:20 +01:00
srcutree.c srcu: Unconditionally record srcu_read_lock_lite() in ->srcu_reader_flavor 2024-11-15 22:13:37 +01:00
sync.c rcu: Eliminate lockless accesses to rcu_sync->gp_count 2024-07-04 13:48:57 -07:00
tasks.h RCU pull request for v6.13 2024-11-19 11:27:07 -08:00
tiny.c softirq: Remove unused 'action' parameter from action callback 2024-08-20 17:13:40 +02:00
tree_exp.h RCU pull request for v6.12 2024-09-18 07:52:24 +02:00
tree_nocb.h rcu/nocb: Fix missed RCU barrier on deoffloading 2024-11-12 22:51:52 +01:00
tree_plugin.h rcu: Use bitwise instead of arithmetic operator for flags 2024-11-12 21:40:53 +01:00
tree_stall.h rcu: Finer-grained grace-period-end checks in rcu_dump_cpu_stacks() 2024-11-03 21:55:35 +01:00
tree.c rcu/kvfree: Fix data-race in __mod_timer / kvfree_call_rcu 2024-11-12 21:51:34 +01:00
tree.h Merge branches 'context_tracking.15.08.24a', 'csd.lock.15.08.24a', 'nocb.09.09.24a', 'rcutorture.14.08.24a', 'rcustall.09.09.24a', 'srcu.12.08.24a', 'rcu.tasks.14.08.24a', 'rcu_scaling_tests.15.08.24a', 'fixes.12.08.24a' and 'misc.11.08.24a' into next.09.09.24a 2024-09-09 00:09:47 +05:30
update.c