Re: xilinx-zynq-a9: cannot set up guest memory 'zynq.ext_ram'

[David Hildenbrand <david@redhat.com>]

On 20.08.21 16:22, Bin Meng wrote:
> Hi Philippe,
> 
> On Fri, Aug 20, 2021 at 10:10 PM Philippe Mathieu-Daudé
> <philmd@redhat.com> wrote:
>>
>> Hi Bin,
>>
>> On 8/20/21 4:04 PM, Bin Meng wrote:
>>> Hi,
>>>
>>> The following command used to work on QEMU 4.2.0, but is now broken
>>> with QEMU head.
>>>
>>> $ qemu-system-arm -M xilinx-zynq-a9 -display none -m 40000000
>>> -nographic -serial /dev/null -serial mon:stdio -monitor null -device
>>> loader,file=u-boot-dtb.bin,addr=0x4000000,cpu-num=0
>>> qemu-system-arm: cannot set up guest memory 'zynq.ext_ram': Cannot
>>> allocate memory
>>>
>>> Any ideas?
>>
>> Richard hit that recently too.
> 
> I hit this when in the VM on Azure pipelines, but I was able to
> reproduce this issue on my local machine.
> 
>>
>> Can you provide:
>>
>> cat /proc/sys/vm/overcommit_kbytes
>> cat /proc/sys/vm/overcommit_memory
>> cat /proc/sys/vm/overcommit_ratio
> 
> $ cat /proc/sys/vm/overcommit_kbytes
> 0
> $ cat /proc/sys/vm/overcommit_memory
> 0
> $ cat /proc/sys/vm/overcommit_ratio
> 50
> 
>>
>> and
>>
>> cat /proc/meminfo
>>
>> (CommitLimit, Committed_AS)
> 
> $ cat /proc/meminfo
> 
> CommitLimit:    12388820 kB
> Committed_AS:    5019088 kB
> 
>> and OOM messages.
> 
> I did not see any OOM messages.

-m 40000000

corresponds to 38 TB if I am not wrong. Is that really what you want?

How much main memory does your system have?

-- 
Thanks,

David / dhildenb