Re: [PATCH] rcutorture: Avoid problematic critical section nesting on RT
From: Scott Wood <hidden>
Date: 2021-08-20 03:23:58
Also in:
linux-rt-users, lkml, rcu
On Tue, 2021-08-17 at 16:40 +0200, Sebastian Andrzej Siewior wrote:
[bigeasy: remove 'preempt_disable(); local_bh_disable(); preempt_enable(); local_bh_enable();' from the examples because this works on RT now. ]
Does it actually work? If preemption is disabled during local_bh_disable, softirq_ctrl.lock won't be taken. If you then get preempted between the preempt_enable() and the local_bh_enable(), and another task tries to do local_bh_disable(), won't it successfully get softirq_ctrl.lock, add to softirq_ctrl.cnt, and proceed right into the critical section? Or am I missing something? -Scott _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel