Re: [Bisected] Regression: Hang on boot in schedule_timeout_interruptible during ACPI init on SMP

From: Glauber Costa
Date: Mon Jul 28 2008 - 11:00:06 EST


On Mon, Jul 28, 2008 at 11:15 AM, Glauber Costa <gcosta@xxxxxxxxxx> wrote:
> On Sat, Jul 26, 2008 at 02:53:11PM -0400, Andrew Drake wrote:
>> I just discovered; the nolapic_timer parameter causes the problem to go
>> away entirely. It doesn't seem to have any nasty side effects, so I'm
>> content to use it. Looking at the dmesg logs, however, I notice that the
>> "last-good" kernel doesn't even try to use the LAPIC timer, but the
>> "first-bad" does. I wasn't able to track down any discernible reason.
> fine, but if you can still help us on this, it would be awesome ;-)
>
> Actually, there is another nasty bug that depends, at least by a first
> impression, on the lapic timer. I'm planning to save a time today to
> look further on your problem.
>>
>> On a side note, that's the first I've ever heard/seen of that parameter,
>> I tried it because I noticed the problems started when the LAPIC timer
>> was successfully set up. I doubt the average user would notice this (you
>> can't even tell unless you pass apic=debug), so I doubt many others would
>> discover this fix/workaround.
>>
>> The question remains, though, why did it go from "don't try" to "try"?
>
> Probably because the order of initialization of smp entities changed a
> bit during this series. Probably the lapic timer is now initialized a
> little bit earlier, before we have the chance to mark it as bad.
>
> If you can send me at least your dmesgs and cpuinfo, it would be really really
> awesome.

Just saw you've already done it.

Will look through it.

many thanks
>> Thanks,
>>
>> Andrew
>>
>



--
Glauber Costa.
"Free as in Freedom"
http://glommer.net

"The less confident you are, the more serious you have to act."
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