[GIT PULL] RCU changes for v6.3
From: Paul E. McKenney
Date: Sat Feb 18 2023 - 14:11:20 EST
Hello, Linus,
Once the merge window opens, please pull the latest RCU git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git tags/rcu.2023.02.10a
# HEAD: bba8d3d17dc2678f9647962900aa421a18c25320: Merge branch 'stall.2023.01.09a' into HEAD (2023-02-02 16:40:07 -0800)
This pull request contains this commit:
dc7c31b07ade ("drivers/base: Remove CONFIG_SRCU")
Which conflicted in -next with this commit:
3a2dbc510c43 ("driver core: fw_devlink: Don't purge child fwnode's consumer links")
Stephen Rothwell's proposed resolution work for me:
https://lore.kernel.org/lkml/20230210124818.2caaa77f@xxxxxxxxxxxxxxxx
The -rcu tree contains a sample resolution merge commit at branch
conflict-resolution.2023.02.10a.
----------------------------------------------------------------
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.
----------------------------------------------------------------
Akira Yokosawa (2):
docs/RCU/rcubarrier: Adjust 'Answer' parts of QQs as definition-lists
docs/RCU/rcubarrier: Right-adjust line numbers in code snippets
Frederic Weisbecker (3):
rcu-tasks: Improve comments explaining tasks_rcu_exit_srcu purpose
rcu-tasks: Remove preemption disablement around srcu_read_[un]lock() calls
rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()
Joel Fernandes (Google) (5):
locktorture: Allow non-rtmutex lock types to be boosted
locktorture: Make the rt_boost factor a tunable
torture: Fix hang during kthread shutdown phase
rcu: Track laziness during boot and suspend
rcu: Disable laziness if lazy-tracking says so
Paul E. McKenney (44):
doc: Further updates to RCU's lockdep.rst
doc: Update NMI-RCU.rst
doc: Update rcubarrier.rst
doc: Update rcu_dereference.rst
rcu: Consolidate initialization and CPU-hotplug code
rcu: Throttle callback invocation based on number of ready callbacks
rcu: Upgrade header comment for poll_state_synchronize_rcu()
rcu: Make RCU_LOCKDEP_WARN() avoid early lockdep checks
rcu: Suppress smp_processor_id() complaint in synchronize_rcu_expedited_wait()
rcu: Test synchronous RCU grace periods at the end of rcu_init()
rcu: Allow expedited RCU CPU stall warnings to dump task stacks
rcu: Add srcu_down_read() and srcu_up_read()
rcu: Add test code for semaphore-like SRCU readers
srcu: Yet more detail for srcu_readers_active_idx_check() comments
srcu: Update comment after the index flip
torture: Seed torture_random_state on CPU
refscale: Provide for initialization failure
torture: make kvm-find-errors.sh check for compressed vmlinux files
torture: Permit double-quoted-string Kconfig options
rcu: Permit string-valued Kconfig options in kvm.sh
doc: Update and wordsmith rculist_nulls.rst
doc: Update rcu.rst
doc: Update stallwarn.rst
doc: Update torture.rst
doc: Update UP.rst
doc: Update rcu.rst URL to RCU publications
doc: Update whatisRCU.rst
refscale: Add tests using SLAB_TYPESAFE_BY_RCU
rcutorture: Drop sparse lock-acquisition annotations
rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
drivers/base: Remove CONFIG_SRCU
drivers/dax: Remove "select SRCU"
drivers/hwtracing/stm: Remove "select SRCU"
drivers/md: Remove "select SRCU"
drivers/net: Remove "select SRCU"
drivers/pci/controller: Remove "select SRCU"
fs: Remove CONFIG_SRCU
fs/btrfs: Remove "select SRCU"
fs/notify: Remove "select SRCU"
fs/quota: Remove "select SRCU"
init: Remove "select SRCU"
kernel/notifier: Remove CONFIG_SRCU
Merge branches 'doc.2023.01.05a', 'fixes.2023.01.23a', 'kvfree.2023.01.03a', 'srcu.2023.01.03a', 'srcu-always.2023.02.02a', 'tasks.2023.01.03a', 'torture.2023.01.05a' and 'torturescript.2023.01.03a' into HEAD
Merge branch 'stall.2023.01.09a' into HEAD
Pingfan Liu (4):
srcu: Delegate work to the boot cpu if using SRCU_SIZE_SMALL
srcu: Fix a misspelling in comment
srcu: Fix the comparision in srcu_invl_snp_seq()
srcu: Remove needless rcu_seq_done() check while holding read lock
Tiezhu Yang (1):
selftests: rcutorture: Use "grep -E" instead of "egrep"
Uladzislau Rezki (Sony) (9):
rcu: Refactor kvfree_call_rcu() and high-level helpers
rcu/kvfree: Switch to a generic linked list API
rcu/kvfree: Move bulk/list reclaim to separate functions
rcu/kvfree: Move need_offload_krc() out of krcp->lock
rcu/kvfree: Use a polled API to speedup a reclaim process
rcu/kvfree: Use READ_ONCE() when access to krcp->head
rcu/kvfree: Carefully reset number of objects in krcp
rcu/kvfree: Split ready for reclaim objects from a batch
rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
Zhao Mengmeng (1):
rcu: Use hlist_nulls_next_rcu() in hlist_nulls_add_tail_rcu()
Zhen Lei (7):
genirq: Fix the return type of kstat_cpu_irqs_sum()
doc: Document CONFIG_RCU_CPU_STALL_CPUTIME=y stall information
doc: Fix htmldocs build warnings of stallwarn.rst
sched: Add helper kstat_cpu_softirqs_sum()
sched: Add helper nr_context_switches_cpu()
rcu: Add RCU stall diagnosis information
rcu: Align the output of RCU CPU stall warning messages
Zqiang (6):
rcu: Make rcu_blocking_is_gp() stop early-boot might_sleep()
srcu: Release early_srcu resources when no longer in use
rcu-tasks: Use accurate runstart time for RCU Tasks boot-time testing
rcu-tasks: Make rude RCU-Tasks work well with CPU hotplug
rcu-tasks: Handle queue-shrink/callback-enqueue race condition
rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
Documentation/RCU/NMI-RCU.rst | 4 +-
Documentation/RCU/UP.rst | 13 +-
Documentation/RCU/lockdep.rst | 13 +-
Documentation/RCU/rcu.rst | 6 +-
Documentation/RCU/rcu_dereference.rst | 21 +-
Documentation/RCU/rcubarrier.rst | 357 +++++------
Documentation/RCU/rculist_nulls.rst | 109 ++--
Documentation/RCU/stallwarn.rst | 135 ++++-
Documentation/RCU/torture.rst | 89 ++-
Documentation/RCU/whatisRCU.rst | 193 +++---
Documentation/admin-guide/kernel-parameters.txt | 11 +
drivers/base/core.c | 42 --
drivers/dax/Kconfig | 1 -
drivers/hwtracing/stm/Kconfig | 1 -
drivers/md/Kconfig | 1 -
drivers/net/Kconfig | 1 -
drivers/pci/controller/Kconfig | 2 +-
fs/btrfs/Kconfig | 1 -
fs/locks.c | 25 -
fs/notify/Kconfig | 1 -
fs/quota/Kconfig | 1 -
include/linux/kernel_stat.h | 14 +-
include/linux/rculist_nulls.h | 2 +-
include/linux/rcupdate.h | 19 +-
include/linux/rcutiny.h | 12 +-
include/linux/rcutree.h | 2 +-
include/linux/srcu.h | 45 ++
include/linux/srcutree.h | 2 +-
init/Kconfig | 1 -
kernel/locking/locktorture.c | 101 ++--
kernel/notifier.c | 3 -
kernel/pid_namespace.c | 17 +
kernel/rcu/Kconfig.debug | 15 +-
kernel/rcu/rcu.h | 8 +
kernel/rcu/rcu_segcblist.c | 2 +-
kernel/rcu/rcu_segcblist.h | 2 +
kernel/rcu/rcutorture.c | 12 +-
kernel/rcu/refscale.c | 250 +++++++-
kernel/rcu/srcutree.c | 98 ++-
kernel/rcu/tasks.h | 85 ++-
kernel/rcu/tiny.c | 9 +-
kernel/rcu/tree.c | 657 ++++++++++++---------
kernel/rcu/tree.h | 19 +
kernel/rcu/tree_exp.h | 43 ++
kernel/rcu/tree_stall.h | 37 +-
kernel/rcu/update.c | 49 +-
kernel/sched/core.c | 5 +
kernel/torture.c | 4 +-
.../selftests/rcutorture/bin/configcheck.sh | 5 +-
.../selftests/rcutorture/bin/console-badness.sh | 2 +-
.../testing/selftests/rcutorture/bin/kvm-build.sh | 4 +-
.../selftests/rcutorture/bin/kvm-find-errors.sh | 6 +-
tools/testing/selftests/rcutorture/bin/kvm.sh | 6 +-
.../selftests/rcutorture/bin/parse-console.sh | 10 +-
54 files changed, 1734 insertions(+), 839 deletions(-)