Re: [PATCH] softirq: Use local_irq_save() in local_bh_enable()

[Ingo Molnar]

* Jarek Poplawski <jarkao2@xxxxxxxxx> wrote:

> This report: http://marc.info/?l=linux-netdev&m=122599341430090&w=2 
> shows local_bh_enable() is used in the wrong context (irqs 
> disabled). It happens when a usual network receive path is called by 
> netconsole, which simply turns off irqs around this all. Probably 
> this is wrong, but it worked like this long time, and it's not 
> trivial to fix this.
> 
> Anyway, a commit 0f476b6d91a1395bda6464e653ce66ea9bea7167 "softirq: 
> remove irqs_disabled warning from local_bh_enable" can break things 
> after changing from local_irq_save() to local_irq_disable(). Before 
> this commit there was only a warning, now a lockup is possible, so 
> it could be treated as a regression. This patch reverts the change 
> in irqs.

hm, but calling local_bh_enable() with hardirqs off is a bug. It might 
be a long-standing bug, but it can cause lockups even with that change 
reverted: when we process softirqs in local_bh_enable(). So why not 
fix the bug instead?

	Ingo
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