Re: The i386 and x86_64 genirq patches are wrong!

[Eric W. Biederman]

Andrew Morton <akpm@xxxxxxxx> writes:

> ebiederm@xxxxxxxxxxxx (Eric W. Biederman) wrote:
>>
>> Ingo Molnar <mingo@xxxxxxx> writes:
>> 
>> > here too it's hard for me to give an answer without seeing your specific 
>> > changes (against whatever base is most convenient to you). MSI certainly 
>> > works fine on current -mm. (at least on my box)
>> 
>> Ok.  Looking closer.  I have found a clear functional bug.
>> 
>> When CONFIG_PCI_MSI is not set.
>>   move_irq expands to move_native_irq.
>> 
>>   ack_ioapic_vector
>>     move_native_irq
>>     ack_ioapic_irq
>>       move_irq
>>         move_native_irq
>> 
>>   ack_ioapic_quirk_vector
>>     move_native_irq
>>     ack_ioapic_quirk_irq
>>       move_irq
>>         move_native_irq
>> 
>> So we wind up calling move_native_irq twice when MSI is disabled where
>> before your conversion we only ever called it once.  Luckily in
>> the case where we have the double call vector_to_irq is a noop so
>> we only migration the same irq twice.
>> 
>
> OK, but this doesn't seem to answer Ingo's request "could you please send
> that fix to me, against whatever base you have it tested on, and i'll merge
> it to genirq/irqchips [and fix up genirq if needed].  Please also include a
> description of the problem.  How common is that edge retrigger problem, and
> how come this has never been seen in the past years since we had
> irqbalance?"
>
> The genirq patches are stuck in limboland until issues like this are
> resolved.  I'm not planning on sending them to Linus for 2.6.18 so there's
> no huge rush on it, but it would be nice to get all these loose ends tied
> off reasonably promptly, please.

Should be in the morning.  The patches are ready I just need to make certain
I copy all of the appropriate people, add signed-off-by lines, etc.
The reason for the delay was that I didn't have a convenient base.  I
had a development effort that as it's final product turned up a bug.

I think everything is in good shape but I don't trust myself until I slept
on it all.

My patches are incremental against 2.6.17-rc6-mm2 as that turned out
to be the easiest place to start.

Eric



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