Messages in this thread | | | Date | Tue, 22 May 2018 11:53:11 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH RT] sched: let softirq_count() return !0 if inside local_bh_disable()ed section |
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On Thu, 17 May 2018 12:22:14 +0200 Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> 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.
Looks to keep the paradigm closer to vanilla Linux to me.
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> > 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 >
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