Re: [PATCH v2] cgroup: disable irqs while holding css_set_lock
From: Daniel Bristot de Oliveira <hidden>
Date: 2016-06-17 00:12:41
Also in:
lkml
From: Daniel Bristot de Oliveira <hidden>
Date: 2016-06-17 00:12:41
Also in:
lkml
On 06/16/2016 07:14 PM, Tejun Heo wrote:
Except that the patch seems to use irqsave/restore instead of plain irq ones in places. Care to update those?
Hi Tejun, The use of the irq spin_(un)lock_irq() assumes that the code is always called with IRQs enabled. But that is not always true in this case, as we call cgroup_free() in the hard IRQ context, and unconditionally enable IRQ in this context is a problem. So we need to use irqsave/restore. Discussing with rostedt, we figured that this needs to be IRQ safe (using irqsave/restore) in the PREEMPT RT too, so I need to code a v3 of this patch using raw_spin_*() functions to avoid this problem in the -rt kernel as well. Do you see any problems on this? Thanks! -- Daniel