Re: [Discuss-gnuradio] Memory allocation issue

[Ron Economos]

The correct syntax is:

sudo sysctl kernel.shmmax=2147483648

for 2 Gbytes.

Ron

On 10/05/2015 10:01 PM, Hitesh Kasera wrote:
> Hello everyone,
> I am trying to implement OFDM TX in GRC but with fft length 2048. 
> according to fft length i have updated syn words, pilot carriers, 
> pilot symbols, occupied carriers. When i run the flow graph i get this 
> error:
>
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::buffer::allocate_buffer: failed to allocate buffer of size 1536000 KB
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::vmcircbuf_sysv_shm: shmget (1): Invalid argument
> gr::buffer::allocate_buffer: failed to allocate buffer of size 1536000 KB
> terminate called after throwing an instance of 'std::bad_alloc'
> what(): std::bad_alloc
>
> Buffer size is around 1.5GB. i tried to set kernel.shmmax to 8GB but 
> its not working. I am using Ubuntu 14.04. Kernel and GNU details are:
> GNU Radio Companion 3.7.8rc1
> GNU C++ version 4.8.4
> UHD_003.009.git-217-g012381d9
> kernel release - 3.13.0-58-generic
> kernel version - #97-Ubuntu SMP
>
> I am new to work with GNU Radio. I am not able to correct this error. 
> If anyone has any idea to correct this please tell me.
>
> Best Regards
> Hitesh