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From: Enlin Mu <enlin.mu@linux.dev>
To: peterz@infradead.org, tglx@kernel.org, boqun@kernel.org,
	lyude@redhat.com, bigeasy@linutronix.de, joelagnelf@nvidia.com,
	linux-kernel@vger.kernel.org, enlin.mu@unisoc.com,
	enlin.mu@linux.dev
Subject: [PATCH v2] softirq: Remove redundant h->action from preempt_count mismatch error
Date: Tue, 25 Aug 2026 09:15:09 +0800	[thread overview]
Message-ID: <20260825011509.8505-1-enlin.mu@linux.dev> (raw)

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@linutronix.de>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Enlin Mu <enlin.mu@unisoc.com>
Signed-off-by: Enlin Mu <enlin.mu@linux.dev>
---
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@linux.dev/
---
 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


             reply	other threads:[~2026-08-25  1:15 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-25  1:15 Enlin Mu [this message]
2026-08-25  6:53 ` [PATCH v2] softirq: Remove redundant h->action from preempt_count mismatch error Sebastian Andrzej Siewior
2026-08-25 13:08 ` Bradley Morgan

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