Why cannot I allocate more than -Xmx700M

[Yuri Khotyaintsev]

Nicklas Johnson wrote:
> 2008/8/18 Sharkie <shark.fin.soup at mac.com>
>
>   
>> I get the following, which I have no idea how to read
>>
>> %kdump -t csu | grep -B 1 errno
>>
>>   1038 java     CALL
>>  mmap(0,0x42800000,PROT_READ|PROT_WRITE|PROT_EXEC,MAP_PRIVATE|MAP_NORESERVE|MAP_ANON,0xffffffff,0,0)
>>   1038 java     RET   mmap -1 errno 12 Cannot allocate memory
>>
>>     
>
> There's your answer.
>
> The JVM is trying to mmap 1064MB of contiguous virtual memory, and the OS
> says "no".
>
> The limitation isn't coming from the JVM.  It's coming from the OS.  The
> problem you'll need to solve is why you can't mmap more.  Either there isn't
> that much contiguous virtual memory left, or you're hitting some other
> system limitation.
>
>   
You can try reducing kern.maxdsiz and kern.dfldsiz in order to give mmap 
more space.

Yuri

-- 
Dr. Yuri Khotyaintsev
Institutet för rymdfysik (IRF), Uppsala