Re: [Discuss-gnuradio] Shared Memory Problem

[Trond Danielsen]

2007/4/12, Eric Blossom <address@hidden>:
> On Thu, Apr 12, 2007 at 02:50:17PM +0200, Trond Danielsen wrote:
> > Hi,
> >
> > I have a problem with insufficent shared memory. I'm running GNU Radio
> > from SVN, and keep getting these messages:
> >
> > gr_vmcircbuf_sysv_shm: shmget (1): No space left on device
> > gr_buffer::allocate_buffer: failed to allocate buffer of size 32 KB
> > terminate called after throwing an instance of 'std::bad_alloc'
> >  what():  St9bad_alloc
> > Avbrutt (SIGABRT)
> >
> > I've tried increasing the maximum size of shared mem blocks with this
> > command:
> > sysctl -w kernel.shmmax=2147483648
> >
> > I've attached the block that causes these problems (it will not work
> > if you try it, because some additional modules are missing). Any hints
> > on how to solve this?
>
> As Greg mentioned, this error is from shmget, and indicates
> that there are not enough shared memory segments available.
>
> Looks like kernel.shmmni may be the parameter that needs tweaking.
> It's 4096 on my machines.

Thanks for the answers! kernel.shmmni is the same as on my machines,
so I doubt that it is the problem . But I have already solved the
problem; Johnathan pointed me to the single pole IIR filter that
solved my problem in a much better way than the solution that I came
up with. Apparently GNU Radio does not like 2000 simultaneous branches
in a single block...

> BTW, I like your use of lambda expressions below:

Saves a lot of typing :)

> >         gr.hier_block2.__init__(self,
> >             "acquisition",
> >             gr.io_signature(1,1,gr.sizeof_gr_complex),
> >             gr.io_signature(1,1, int(self.fft_size * gr.sizeof_float)))
> >
> >         # aliases:
> >         c = lambda i, o, i_p=0, o_p=0: self.connect(i,i_p,o,o_p)
> >         d = lambda n, f: self.define_component( n, f)
> >
> >         # Input signal; get Fourier transform of signal.
> >         d( "s2v_input",
> >             gr.stream_to_vector(gr.sizeof_gr_complex, self.fft_size))
> >         d( "fft_input",
> >             gr.fft_vcc(self.fft_size, True, self.window))
>
> Eric


--
Trond Danielsen