From: Eugeniu Rosca <erosca@de.adit-jv.com>
To: <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Will Deacon <will@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Jiafei Pan <Jiafei.Pan@nxp.com>,
Romain Perier <romain.perier@gmail.com>
Cc: Andrew Gabbasov <andrew_gabbasov@mentor.com>,
Dirk Behme <dirk.behme@de.bosch.com>,
Eugeniu Rosca <roscaeugeniu@gmail.com>,
Eugeniu Rosca <erosca@de.adit-jv.com>
Subject: [PATCH v2] softirq: s/BUG/WARN_ONCE/ on tasklet SCHED state not set
Date: Wed, 17 Mar 2021 11:20:12 +0100 [thread overview]
Message-ID: <20210317102012.32399-1-erosca@de.adit-jv.com> (raw)
From: Dirk Behme <dirk.behme@de.bosch.com>
Replace BUG() with WARN_ONCE() on wrong tasklet state, in order to:
* increase the verbosity / aid in debugging
* avoid fatal/unrecoverable state
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
Changes since v1:
* Factored out the change into a separate function
* Replaced BUG with WARN_ONCE
* Fixed 'checkpatch --strict' errors
* v1: https://lore.kernel.org/lkml/20210315154421.11463-1-erosca@de.adit-jv.com/
kernel/softirq.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 9908ec4a9bfe..17a93d47b9a1 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -531,6 +531,18 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
}
EXPORT_SYMBOL(__tasklet_hi_schedule);
+static bool tasklet_should_run(struct tasklet_struct *t)
+{
+ if (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+ return true;
+
+ WARN_ONCE(1, "tasklet SCHED state not set: %s %pS\n",
+ t->use_callback ? "callback" : "func",
+ t->use_callback ? (void *)t->callback : (void *)t->func);
+
+ return false;
+}
+
static void tasklet_action_common(struct softirq_action *a,
struct tasklet_head *tl_head,
unsigned int softirq_nr)
@@ -550,13 +562,12 @@ static void tasklet_action_common(struct softirq_action *a,
if (tasklet_trylock(t)) {
if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED,
- &t->state))
- BUG();
- if (t->use_callback)
- t->callback(t);
- else
- t->func(t->data);
+ if (tasklet_should_run(t)) {
+ if (t->use_callback)
+ t->callback(t);
+ else
+ t->func(t->data);
+ }
tasklet_unlock(t);
continue;
}
--
2.29.0
next reply other threads:[~2021-03-17 10:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 10:20 Eugeniu Rosca [this message]
2021-03-17 12:38 ` [tip: irq/core] softirq: s/BUG/WARN_ONCE/ on tasklet SCHED state not set tip-bot2 for Dirk Behme
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