A question about the softirq implementation in DDE Linux26

Da Zheng zhengda1936 at gmail.com
Mon Mar 1 13:32:22 CET 2010


Hi,

On 10-3-1 下午5:58, Christian Helmuth wrote:
>> If you only consider about handling the softirq queue, I think it's easy, simply
>> using a lock to protect it explicitly, but it cannot solve the problem
>> completely. There should be many race conditions in other places. I implement
>> raw_local_irq_disable() and raw_local_irq_enable() with a lock, but there is
>> still a serious problem. Because of spin_lock_irqsave, there can be dead locks.
>> One example is in pcnet32_watchdog() and pcnet32_interrupt(). So I think we can
>> just let spin_lock_irqsave() become spin_lock(). After all, the interrupt
>> handling doesn't run in the real interrupt context any more, so I think there is
>> no reason to do spin_lock_irqsave() or spin_lock_irq().
> 
> Sounds like my idea behind the current scheme. Thanks for your input
> on this.
I have one implementation and I sent it to the mailing list. Could you please
check if it works? If possible, try it on your DDE. It works for my pcnet32 driver.

Best regards,
Zheng Da




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