On Mon, Jul 07, 2025 at 09:22:48PM -0400, Steven Rostedt wrote:
quoted hunk ↗ jump to hunk
@@ -143,6 +144,7 @@ static void unwind_deferred_task_work(struct callback_head *head)
struct unwind_stacktrace trace;
struct unwind_work *work;
u64 cookie;
+ int idx;
if (WARN_ON_ONCE(!local_read(&info->pending)))
return;
@@ -161,13 +163,15 @@ static void unwind_deferred_task_work(struct callback_head *head)
cookie = info->id.id;
- guard(mutex)(&callback_mutex);
- list_for_each_entry(work, &callbacks, list) {
+ idx = srcu_read_lock(&unwind_srcu);
+ list_for_each_entry_srcu(work, &callbacks, list,
+ srcu_read_lock_held(&unwind_srcu)) {
if (test_bit(work->bit, &info->unwind_mask)) {
work->func(work, &trace, cookie);
clear_bit(work->bit, &info->unwind_mask);
}
}
+ srcu_read_unlock(&unwind_srcu, idx);
}
Please; something like so:
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -524,4 +524,9 @@ DEFINE_LOCK_GUARD_1(srcu, struct srcu_st
srcu_read_unlock(_T->lock, _T->idx),
int idx)
+DEFINE_LOCK_GUARD_1(srcu_lite, struct srcu_struct,
+ _T->idx = srcu_read_lock_lite(_T->lock),
+ srcu_read_unlock_lite(_T->lock, _T->idx),
+ int idx)
+
#endif
--- a/kernel/unwind/deferred.c
+++ b/kernel/unwind/deferred.c
@@ -165,7 +165,7 @@ static void unwind_deferred_task_work(st
cookie = info->id.id;
- guard(mutex)(&callback_mutex);
+ guard(srcu_lite)(&unwind_srcu);
list_for_each_entry(work, &callbacks, list) {
work->func(work, &trace, cookie);
}