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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 12:16:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 12:16:14 -0700 |
commit | 5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c (patch) | |
tree | 16ab52c0a14ff9421a9f55848705ee76b5a9ce6e /Documentation/RCU/Design | |
parent | 5d77652fbf2318f61af2cf27779951393dd0f749 (diff) | |
parent | 8ae99857748bece993962dd8d04e096f9e76731f (diff) | |
download | linux-stable-5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c.tar.gz linux-stable-5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c.tar.bz2 linux-stable-5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c.zip |
Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux
Pull RCU updates from Joel Fernandes:
- Updates and additions to MAINTAINERS files, with Boqun being added to
the RCU entry and Zqiang being added as an RCU reviewer.
I have also transitioned from reviewer to maintainer; however, Paul
will be taking over sending RCU pull-requests for the next merge
window.
- Resolution of hotplug warning in nohz code, achieved by fixing
cpu_is_hotpluggable() through interaction with the nohz subsystem.
Tick dependency modifications by Zqiang, focusing on fixing usage of
the TICK_DEP_BIT_RCU_EXP bitmask.
- Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
kernels, fixed by Zqiang.
- Improvements to rcu-tasks stall reporting by Neeraj.
- Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
increased robustness, affecting several components like mac802154,
drbd, vmw_vmci, tracing, and more.
A report by Eric Dumazet showed that the API could be unknowingly
used in an atomic context, so we'd rather make sure they know what
they're asking for by being explicit:
https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/
- Documentation updates, including corrections to spelling,
clarifications in comments, and improvements to the srcu_size_state
comments.
- Better srcu_struct cache locality for readers, by adjusting the size
of srcu_struct in support of SRCU usage by Christoph Hellwig.
- Teach lockdep to detect deadlocks between srcu_read_lock() vs
synchronize_srcu() contributed by Boqun.
Previously lockdep could not detect such deadlocks, now it can.
- Integration of rcutorture and rcu-related tools, targeted for v6.4
from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
module parameter, and more
- Miscellaneous changes, various code cleanups and comment improvements
* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
checkpatch: Error out if deprecated RCU API used
mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
rcu/trace: use strscpy() to instead of strncpy()
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
...
Diffstat (limited to 'Documentation/RCU/Design')
-rw-r--r-- | Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst | 6 | ||||
-rw-r--r-- | Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst | 2 |
2 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst index c9c957c85bac..93d899d53258 100644 --- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst +++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst @@ -277,7 +277,7 @@ the following access functions: Again, only one request in a given batch need actually carry out a grace-period operation, which means there must be an efficient way to -identify which of many concurrent reqeusts will initiate the grace +identify which of many concurrent requests will initiate the grace period, and that there be an efficient way for the remaining requests to wait for that grace period to complete. However, that is the topic of the next section. @@ -405,7 +405,7 @@ Use of Workqueues In earlier implementations, the task requesting the expedited grace period also drove it to completion. This straightforward approach had the disadvantage of needing to account for POSIX signals sent to user -tasks, so more recent implemementations use the Linux kernel's +tasks, so more recent implementations use the Linux kernel's workqueues (see Documentation/core-api/workqueue.rst). The requesting task still does counter snapshotting and funnel-lock @@ -465,7 +465,7 @@ corresponding disadvantage that workqueues cannot be used until they are initialized, which does not happen until some time after the scheduler spawns the first task. Given that there are parts of the kernel that really do want to execute grace periods during this mid-boot “dead -zone”, expedited grace periods must do something else during thie time. +zone”, expedited grace periods must do something else during this time. What they do is to fall back to the old practice of requiring that the requesting task drive the expedited grace period, as was the case before diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst index 7fdf151a8680..5750f125361b 100644 --- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst +++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst @@ -168,7 +168,7 @@ an ``atomic_add_return()`` of zero) to detect idle CPUs. +-----------------------------------------------------------------------+ The approach must be extended to handle one final case, that of waking a -task blocked in ``synchronize_rcu()``. This task might be affinitied to +task blocked in ``synchronize_rcu()``. This task might be affined to a CPU that is not yet aware that the grace period has ended, and thus might not yet be subject to the grace period's memory ordering. Therefore, there is an ``smp_mb()`` after the return from |