Re: 3.9-rc1: crash kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer

Yinghai Lu
2013-03-08T06:32:41Z

On Thu, Mar 7, 2013 at 10:03 PM, CAI Qian <caiqian@redhat.com> wrote:
> CC'ing kexec ML. Also mentioned that 3.8 has no such issue.
>
> This message looks suspicious and out of range while 3.8 reservation
> looks within the range.
>
> [ 0.000000] Reserving 128MB of memory at 5216MB for crashkernel
> (System RAM: 3977MB)
>
> Wondering if anything to do with memblock again...

that is intended...

> ----- Original Message -----
>> From: "WANG Chao" <chaowang@redhat.com>
>> To: "LKML" vger.kernel.org>
>> Cc: "CAI Qian" <caiqian@redhat.com>
>> Sent: Friday, March 8, 2013 1:54:37 PM
>> Subject: 3.9-rc1: crash kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you
>> with the DMA bounce buffer
>>
>> Hi, All
>>
>> On 3.9-rc1, I load crash kernel with latest kexec-tools(up to
>> 28d413a), but
>> 2nd kernel panic at early time:
>> [ 2.948076] Kernel panic - not syncing: Can not allocate SWIOTLB
>> buffer earlier and can't now provide you with the DMA bounce buffer
>> [ 2.959958] Pid: 53, comm: khubd Not tainted 3.9.0-rc1+ #1

You need to add crashkernel_low=64M in first kernel.

As your system does not support DMA remapping.

Thanks