[CFT] SIFTR - Statistical Information For TCP Research: Uncle
Lawrence needs YOU!
lstewart at freebsd.org
Tue Jun 22 02:06:47 UTC 2010
On 06/22/10 04:52, Fabian Keil wrote:
> Lawrence Stewart<lstewart at freebsd.org> wrote:
>> On 06/21/10 05:44, Rui Paulo wrote:
>>> On 20 Jun 2010, at 20:36, Fabian Keil wrote:
>>>> Fabian Keil<freebsd-listen at fabiankeil.de> wrote:
>>>>> Fabian Keil<freebsd-listen at fabiankeil.de> wrote:
>>>>>> My custom kernel normally doesn't have INVARIANTS and WITNESS
>>>>>> enabled, so I'll try to enable them next.
>>>>> The culprit seem to be non-default KTR settings in the kernel
>>>>> while loading alq as a module.
>>>> Actually whether or not alq is loaded as a module doesn't
>>>> seem to matter, with:
>>>> options KTR
>>>> options KTR_ENTRIES=262144
>>>> options KTR_COMPILE=(KTR_SCHED)
>>>> options KTR_MASK=(KTR_SCHED)
>>>> options KTR_CPUMASK=0x3
>>>> options ALQ
>>>> options KTR_ALQ
>>>> enabling siftr panics the system, too.
>>> That's probably because your module was built with different compile time options than the ones used in the kernel. These options may change structure sizes, function parameters, etc. and that easily causes panics.
>> hmm I wonder if my instructions to build SIFTR manually are causing your
>> problems. Fabian, is the siftr.ko module you're loading built as part of
>> a "make buildkernel", or did you follow my instructions and "cd
>> </path/to/src>/sys/modules/siftr ; make ; kldload ./siftr.ko"?
> The latter.
>> If the latter is true, perhaps try and explicitly build SIFTR as part of
>> "make buildkernel" and see if loading the module built that way still
>> triggers the panic when enabled (the module will be in
>> or if you "make installkernel" it'll be in /boot/kernel/kernel/siftr.ko).
> That seems to work.
Damn, well this is the first time I've encountered a problem like this
whilst using SIFTR compiled standalone and I've been using it like that
for almost 3 years. I guess the lack of KTR in the module build subtly
influences the module in a way that allows it load but in a precarious
way. How irritating. Rui you were right on the money!
I will revise my testing instructions to build the module as part of a
buildkernel to avoid potential problems like this.
Thanks for helping get to the bottom of this and for the test feedback.
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