Re: Help with 2.6.10 concurrency issue

[Robert Hancock <hancockr@shaw.ca>]

martin rogers wrote:
> Problem is, the function writeList can be called from a H/W intr,
> and a workqueue (and that intr could of course happen while either
> the workqueue or the tasklet is running, right?).
> 
> If I use spin_lock_irqsave in writeList, it protects against the intr
> but not the tasklet.

Yes, it protects against the tasklet as well. Disabling interrupts also 
implicity disables BH execution (tasklets).

   If I use spin_lock_bh, I don't get protection
> from the intr I think; plus, I get :
> 
> Badness in local_bh_enable at kernel/softirq.c:142
> 
> when the intr runs (what does this mean?).

It means you're enabling BHs when interrupts are disabled, which doesn't 
make any sense. You can't use spin_lock_bh/spin_unlock_bh when 
interrupts are disabled.

-- 
Robert Hancock      Saskatoon, SK, Canada
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