Hello, Linus,
Please pull this RCU update into the v6.18 merge window:
git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux tags/rcu.2025.09.26a
# HEAD: 1d289fc5691c7a970a285bc53292bac9e37c89a6: Merge branch
'torture.2025.08.14a' into HEAD (2025-09-23 02:10:51 -0700)
----------------------------------------------------------------
RCU pull request for v6.18
This pull request contains the following branches, non-octopus merged:
Documentation updates:
- Update whatisRCU.rst and checklist.rst for recent RCU API additions.
- Fix RCU documentation formatting and typos.
- Replace dead Ottawa Linux Symposium links in RTFP.txt.
Miscellaneous RCU updates:
- Document that rcu_barrier() hurries RCU_LAZY callbacks.
- Remove redundant interrupt disabling from
rcu_preempt_deferred_qs_handler().
- Move list_for_each_rcu from list.h to rculist.h, and adjust the
include directive in kernel/cgroup/dmem.c accordingly.
- Make initial set of changes to accommodate upcoming system_percpu_wq
changes.
SRCU updates:
- Create an srcu_read_lock_fast_notrace() for eventual use in tracing,
including adding guards.
- Document the reliance on per-CPU operations as implicit RCU readers
in __srcu_read_{,un}lock_fast().
- Document the srcu_flip() function's memory-barrier D's relationship
to SRCU-fast readers.
- Remove a redundant preempt_disable() and preempt_enable() pair from
srcu_gp_start_if_needed().
Torture-test updates:
- Fix jitter.sh spin time so that it actually varies as advertised.
It is still quite coarse-grained, but at least it does now vary.
- Update torture.sh help text to include the not-so-new --do-normal
parameter, which permits (for example) testing KCSAN kernels without
doing non-debug kernels.
- Fix a number of false-positive diagnostics that were being triggered
by rcutorture starting before boot completed. Running multiple
near-CPU-bound rcutorture processes when there is only the boot CPU
is after all a bit excessive.
- Substitute kcalloc() for kzalloc().
- Remove a redundant kfree() and NULL out kfree()ed objects.
----------------------------------------------------------------
Akira Yokosawa (1):
rcu: docs: Requirements.rst: Abide by conventions of kernel documentation
Andy Shevchenko (1):
rculist: move list_for_each_rcu() to where it belongs
Bagas Sanjaya (3):
Documentation: RCU: Wrap kvm-remote.sh rerun snippet in literal code block
Documentation: RCU: Reduce toctree depth
Documentation: RCU: Retitle toctree index
Kaushlendra Kumar (2):
refperf: Remove redundant kfree() after torture_stop_kthread()
refperf: Set reader_tasks to NULL after kfree()
Marco Crivellari (3):
rcu: replace use of system_wq with system_percpu_wq
rcu: WQ_PERCPU added to alloc_workqueue users
rcu: WQ_UNBOUND added to sync_wq workqueue
Nikil Paul S (1):
docs: rcu: Replace multiple dead OLS links in RTFP.txt
Paul E. McKenney (20):
rcu: Document that rcu_barrier() hurries lazy callbacks
srcu: Move rcu_is_watching() checks to srcu_read_{,un}lock_fast()
srcu: Add srcu_read_lock_fast_notrace() and
srcu_read_unlock_fast_notrace()
srcu: Add guards for notrace variants of SRCU-fast readers
rcutorture: Fix jitter.sh spin time
torture: Add --do-normal parameter to torture.sh help text
torture: Announce kernel boot status at torture-test startup
rcutorture: Suppress "Writer stall state" reports during boot
rcutorture: Delay rcutorture readers and writers until boot completes
torture: Delay CPU-hotplug operations until boot completes
rcutorture: Delay forward-progress testing until boot completes
doc: Update whatisRCU.rst for recent RCU API additions
doc: Add RCU guards to checklist.rst
doc: Fix typo in RCU's torture.rst documentation
Merge branch 'doc.2025.08.20a' into HEAD
srcu: Document __srcu_read_{,un}lock_fast() implicit RCU readers
srcu: Document srcu_flip() memory-barrier D relation to SRCU-fast
Merge branch 'rcu.2025.09.23a' into HEAD
Merge branch 'srcu-next.2025.08.21a' into HEAD
Merge branch 'torture.2025.08.14a' into HEAD
Qianfeng Rong (2):
rcutorture: Use kcalloc() instead of kzalloc()
refscale: Use kcalloc() instead of kzalloc()
Zqiang (2):
rcu: Remove local_irq_save/restore() in rcu_preempt_deferred_qs_handler()
srcu/tiny: Remove preempt_disable/enable() in srcu_gp_start_if_needed()
.../RCU/Design/Requirements/Requirements.rst | 52 ++++---
Documentation/RCU/RTFP.txt | 6 +-
Documentation/RCU/checklist.rst | 27 ++--
Documentation/RCU/index.rst | 6 +-
Documentation/RCU/torture.rst | 4 +-
Documentation/RCU/whatisRCU.rst | 150 ++++++++++++++++-----
include/linux/list.h | 10 --
include/linux/rculist.h | 10 ++
include/linux/srcu.h | 34 +++++
include/linux/srcutree.h | 49 ++++---
kernel/cgroup/dmem.c | 1 +
kernel/rcu/rcutorture.c | 27 +++-
kernel/rcu/refscale.c | 4 +-
kernel/rcu/srcutiny.c | 4 +-
kernel/rcu/srcutree.c | 10 ++
kernel/rcu/tasks.h | 4 +-
kernel/rcu/tree.c | 9 +-
kernel/rcu/tree_plugin.h | 5 +-
kernel/torture.c | 7 +-
tools/testing/selftests/rcutorture/bin/jitter.sh | 27 +++-
tools/testing/selftests/rcutorture/bin/torture.sh | 1 +
21 files changed, 317 insertions(+), 130 deletions(-)
