[PATCH v2] softirq: Remove redundant h->action from preempt_count mismatch error
From: Enlin Mu
Date: Mon Aug 24 2026 - 21:15:30 EST
When a preempt_count mismatch is detected in handle_softirqs(), the
error message currently prints the softirq action handler (h->action).
However, as Thomas Gleixner pointed out, the action handler for a given
softirq vector is always a known, fixed function (e.g., run_timer_softirq
for TIMER_SOFTIRQ). Printing it provides zero diagnostic value. The real
issue typically lies in the functions invoked *within* that handler, not
the handler entry point itself.
Therefore, as suggested by Sebastian Andrzej Siewior, remove h->action
from the print statement entirely to clean up the error message.
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Enlin Mu <enlin.mu@xxxxxxxxxx>
Signed-off-by: Enlin Mu <enlin.mu@xxxxxxxxx>
---
v1 -> v2:
- Instead of changing %p to %pS, remove h->action from the print
entirely as suggested by Sebastian and Thomas.
- Update commit message accordingly.
v1: https://lore.kernel.org/all/20260105094133.3542-1-enlin.mu@xxxxxxxxx/
---
kernel/softirq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 7980a4a232f9..800d81c57302 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -645,8 +645,8 @@ static void handle_softirqs(bool ksirqd)
h->action();
trace_softirq_exit(vec_nr);
if (unlikely(prev_count != preempt_count())) {
- pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
- vec_nr, softirq_to_name[vec_nr], h->action,
+ pr_err("huh, entered softirq %u %s with preempt_count %08x, exited with %08x?\n",
+ vec_nr, softirq_to_name[vec_nr],
prev_count, preempt_count());
preempt_count_set(prev_count);
}
--
2.39.5