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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 /kernel/rcu/tree_exp.h | |
parent | 5d77652fbf2318f61af2cf27779951393dd0f749 (diff) | |
parent | 8ae99857748bece993962dd8d04e096f9e76731f (diff) | |
download | linux-5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c.tar.gz linux-5dfb75e842e0ef59fc7bf307e5c52eab215bdb4c.tar.bz2 linux-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 'kernel/rcu/tree_exp.h')
-rw-r--r-- | kernel/rcu/tree_exp.h | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 249c2967d9e6..3b7abb58157d 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -594,6 +594,7 @@ static void synchronize_rcu_expedited_wait(void) struct rcu_data *rdp; struct rcu_node *rnp; struct rcu_node *rnp_root = rcu_get_root(); + unsigned long flags; trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("startwait")); jiffies_stall = rcu_exp_jiffies_till_stall_check(); @@ -602,17 +603,17 @@ static void synchronize_rcu_expedited_wait(void) if (synchronize_rcu_expedited_wait_once(1)) return; rcu_for_each_leaf_node(rnp) { + raw_spin_lock_irqsave_rcu_node(rnp, flags); mask = READ_ONCE(rnp->expmask); for_each_leaf_node_cpu_mask(rnp, cpu, mask) { rdp = per_cpu_ptr(&rcu_data, cpu); if (rdp->rcu_forced_tick_exp) continue; rdp->rcu_forced_tick_exp = true; - preempt_disable(); if (cpu_online(cpu)) tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP); - preempt_enable(); } + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } j = READ_ONCE(jiffies_till_first_fqs); if (synchronize_rcu_expedited_wait_once(j + HZ)) @@ -802,9 +803,11 @@ static int rcu_print_task_exp_stall(struct rcu_node *rnp) int ndetected = 0; struct task_struct *t; - if (!READ_ONCE(rnp->exp_tasks)) - return 0; raw_spin_lock_irqsave_rcu_node(rnp, flags); + if (!rnp->exp_tasks) { + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); + return 0; + } t = list_entry(rnp->exp_tasks->prev, struct task_struct, rcu_node_entry); list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) { @@ -1065,9 +1068,10 @@ unsigned long start_poll_synchronize_rcu_expedited(void) if (rcu_init_invoked()) raw_spin_lock_irqsave(&rnp->exp_poll_lock, flags); if (!poll_state_synchronize_rcu(s)) { - rnp->exp_seq_poll_rq = s; - if (rcu_init_invoked()) + if (rcu_init_invoked()) { + rnp->exp_seq_poll_rq = s; queue_work(rcu_gp_wq, &rnp->exp_poll_wq); + } } if (rcu_init_invoked()) raw_spin_unlock_irqrestore(&rnp->exp_poll_lock, flags); |