panic: UMA: Increase vm.boot_pages with 32 CPUs

Jim Harris jim.harris at gmail.com
Wed Aug 14 16:21:48 UTC 2013


On Tue, Aug 13, 2013 at 8:47 PM, Jeff Roberson <jroberson at jroberson.net>wrote:

> On Tue, 13 Aug 2013, Jim Harris wrote:
>
>
>>
>>
>> On Tue, Aug 13, 2013 at 3:05 PM, Jeff Roberson <jroberson at jroberson.net>
>> wrote:
>>
>> It's not any one commit really, just creeping demand for more pages
>> before the VM can get started.  I would suggest making boot pages
>> scale with MAXCPU.  Or just raising it as the panic suggests.  We
>> could rewrite the way that the vm gets these early pages but it's a
>> lot of work and typically people just bump it and forget about it.
>>
>>
>> I ran into this problem today when enabling hyperthreading on my
>> dual-socket
>> Xeon E5 system.
>>
>> It looks like r254025 is actually the culprit.  Specifically, the new
>> mallocinit()/kmeminit() now invoke the new vmem_init() before
>> uma_startup2(), which allocates 16 zones out of the boot pages if I am
>> reading this correctly.  This is all done before uma_startup2() is called,
>> triggering the panic.
>>
>>
> I just disabled the quantum caches in vmem which allocate those 16 zones.
> This may alleviate the problem for now.
>
> Thanks,
> Jeff
>
>
Yes - this does alleviate the problem.  Thanks!

-Jim


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