percpu-refcount: improve WARN messages
percpu_ref's WARN messages can be a lot more helpful by indicating
who's the culprit. Make them report the release function that the
offending percpu-refcount is associated with. This should make it a
lot easier to track down the reported invalid refcnting operations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index ff99032..70d28c9 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -145,8 +145,9 @@
atomic_add((int) count - PCPU_COUNT_BIAS, &ref->count);
- WARN_ONCE(atomic_read(&ref->count) <= 0, "percpu ref <= 0 (%i)",
- atomic_read(&ref->count));
+ WARN_ONCE(atomic_read(&ref->count) <= 0,
+ "percpu ref (%pf) <= 0 (%i) after killed",
+ ref->release, atomic_read(&ref->count));
/* @ref is viewed as dead on all CPUs, send out kill confirmation */
if (ref->confirm_kill)
@@ -178,7 +179,8 @@
percpu_ref_func_t *confirm_kill)
{
WARN_ONCE(ref->pcpu_count_ptr & PCPU_REF_DEAD,
- "percpu_ref_kill() called more than once!\n");
+ "percpu_ref_kill() called more than once on %pf!",
+ ref->release);
ref->pcpu_count_ptr |= PCPU_REF_DEAD;
ref->confirm_kill = confirm_kill;