From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-rt-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH RT] sched: let softirq_count() return !0 if inside local_bh_disable()ed section
Date: Thu, 17 May 2018 12:22:14 +0200 [thread overview]
Message-ID: <20180517102214.orea3ol6dj7wvpf5@linutronix.de> (raw)
I don't see a reason why softirq_count() shouldn't reflect the fact that
we are within a local_bh_disable() section. I *think* it was done
primary because in RT the softirq is slightly different (and
preemptible) and it broke some of RCU's assumptions.
I don't see any fallout with this change. Furthermore, all checks like
"WARN_ON(!softirq_count())" will work and we can drop the workaround we
currently have in the queue.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/preempt.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 0591df500e9d..d8c05a2626ca 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -91,7 +91,7 @@
# define softirq_count() (preempt_count() & SOFTIRQ_MASK)
# define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
#else
-# define softirq_count() (0UL)
+# define softirq_count() (current->softirq_nestcnt)
extern int in_serving_softirq(void);
#endif
--
2.17.0
next reply other threads:[~2018-05-17 10:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 10:22 Sebastian Andrzej Siewior [this message]
2018-05-22 15:53 ` [PATCH RT] sched: let softirq_count() return !0 if inside local_bh_disable()ed section Steven Rostedt
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