Re: [Discuss-gnuradio] seg fault in volk_32f_s32f_multiply_32f_a_sse gnuradio v 3.6.1

[Tom Rondeau]

On Mon, Sep 3, 2012 at 10:36 PM, ikjtel <address@hidden> wrote:
>
>> The reason this doesn't cause a problem for you in 3.3 is because
>> that's pre-Volk. This looks like you're running SSE operations on a
>> system that doesn't support it.
>
> Hi Tom
> I shall put together the full list of stuff you mentioned, but 3 quick things
>
> 1) the system apparently does support SSE (see below)

Yes, looks like it. But it's an Atom, which might change things. I
know we had some issues on Atom's before, but I thought that we worked
them out. I'll be interested to see how cmake reports the architecture
checks for VOLK here.

> 2) we have a few custom C++ blocks in the app, perhaps there's some rule 
> we're breaking and so running afoul of the SSE instruction operand alignment 
> restrictions (is this possible?)
> 3) the problem is happening in a relatively complex GR app 
> [http://op25.osmocom.org/wiki/wiki/SignalScopePage , using audio-IF mode].
>
> Both 2 and 3 point toward the need to try to reproduce the problem here with 
> a simplified test app, finding the absolute minimum number of GR blocks 
> needed to do so, and ruling out the possibility that's it's something we're 
> doing wrong...
>
> Thanks
>
> Max

Thanks. Not sure what to make of that, yet. What happens if you just
have a sig_source_f->multiply_ff->null_sink?

Tom


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~processor
   : 0
> vendor_id    : GenuineIntel
> cpu family    : 6
> model        : 28
> model name    : Intel(R) Atom(TM) CPU N450   @ 1.66GHz
> stepping    : 10
> cpu MHz        : 1000.000
> cache size    : 512 KB
> physical id    : 0
> siblings    : 2
> core id        : 0
> cpu cores    : 1
> apicid        : 0
> initial apicid    : 0
> fdiv_bug    : no
> hlt_bug        : no
> f00f_bug    : no
> coma_bug    : no
> fpu        : yes
> fpu_exception    : yes
> cpuid level    : 10
> wp        : yes
> flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat 
> clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc 
> arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 cx16 
> xtpr pdcm movbe lahf_lm dts
> bogomips    : 3333.52
> clflush size    : 64
> cache_alignment    : 64
> address sizes    : 32 bits physical, 48 bits virtual
> power management:
>
> processor    : 1
> vendor_id    : GenuineIntel
> cpu family    : 6
> model        : 28
> model name    : Intel(R) Atom(TM) CPU N450   @ 1.66GHz
> stepping    : 10
> cpu MHz        : 1000.000
> cache size    : 512 KB
> physical id    : 0
> siblings    : 2
> core id        : 0
> cpu cores    : 1
> apicid        : 1
> initial apicid    : 1
> fdiv_bug    : no
> hlt_bug        : no
> f00f_bug    : no
> coma_bug    : no
> fpu        : yes
> fpu_exception    : yes
> cpuid level    : 10
> wp        : yes
> flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat 
> clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc 
> arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 cx16 
> xtpr pdcm movbe lahf_lm dts
> bogomips    : 3332.92
> clflush size    : 64
> cache_alignment    : 64
> address sizes    : 32 bits physical, 48 bits virtual
> power management: