FWW this is the output from faddr2line for Linux 6.8.11:
$ scripts/faddr2line --list vmlinux blk_try_enter_queue+0xc/0x75
blk_try_enter_queue+0xc/0x75:
__ref_is_percpu at include/linux/percpu-refcount.h:174 (discriminator 2)
169 * READ_ONCE() is required when fetching it.
170 *
171 * The dependency ordering from the READ_ONCE() pairs
172 * with smp_store_release() in __percpu_ref_switch_to_percpu().
173 */
>174< percpu_ptr = READ_ONCE(ref->percpu_count_ptr);
175
176 /*
177 * Theoretically, the following could test just ATOMIC; however,
178 * then we'd have to mask off DEAD separately as DEAD may be
179 * visible without ATOMIC if we race with percpu_ref_kill(). DEAD
(inlined by) percpu_ref_tryget_live_rcu at
include/linux/percpu-refcount.h:282 (discriminator 2)
277 unsigned long __percpu *percpu_count;
278 bool ret = false;
279
280 WARN_ON_ONCE(!rcu_read_lock_held());
281
>282< if (likely(__ref_is_percpu(ref, &percpu_count))) {
283 this_cpu_inc(*percpu_count);
284 ret = true;
285 } else if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)) {
286 ret = atomic_long_inc_not_zero(&ref->data->count);
287 }
(inlined by) blk_try_enter_queue at block/blk.h:43 (discriminator 2)
38 void submit_bio_noacct_nocheck(struct bio *bio);
39
40 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
41 {
42 rcu_read_lock();
>43< if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
44 goto fail;
45
46 /*
47 * The code that increments the pm_only counter must ensure that the
48 * counter is globally visible before the queue is unfrozen.
