Re: [Discuss-gnuradio] Ubuntu: Pybombs install UHD hangs at 6%?

[Chris Kuethe]

I'm not sure that adding more swap would help; generally the problem
is that disk is thousands of times slower than RAM.

I sampled a few of my rPi machines and they can peak at 20MB/s
sustained read (ie. the fastest possible operation). I'd say you'd be
lucky to get quarter of that on random writes. Someone else has
already done the work of benchmarking and it looks like at worst, ram
is going to be 10x faster than sdcard at its best. Swap is fine for
emergencies or pages you don't really need very often at all, but
really... stay the heck away from swap.

http://www.roylongbottom.org.uk/Raspberry%20Pi%20Benchmarks.htm#anchor9

On Wed, Oct 16, 2019 at 1:32 PM Eamon Heaney <address@hidden> wrote:
>
> Thanks all, it makes sense that I'd be running out of memory on an old Pi. 
> Looks like my swap space was only 128MB, so maybe I'll bump that up just in 
> case.
>
> And thanks for the link, Chris; I should be able to get my hands on a Pi 3 
> with 2GB ram, hopefully that'll cut compile time.
>
> On Wed, Oct 16, 2019 at 4:25 PM Chris Kuethe <address@hidden> wrote:
>>
>> It's not hanging at the install, it's hanging during the build.
>>
>> With that little bit of pedantry out of the way, I'm going to *guess*
>> that you're running out of RAM and starting to hit swap. `htop`,
>> `top`, or `free` would show you if you're swapping. If that's the
>> case, you could try turning down the the number of parallel jobs to 1,
>> eg. only 1 gcc process at a time. This might allow the compile to
>> succeed. You might also need to reduce optimization levels. It sounds
>> a lot like you're having much the same problem as this guy
>> (https://www.raspberrypi.org/forums/viewtopic.php?t=169608) ... 6hrs
>> down to 7minutes when he's not getting swapped to death.
>>
>> On Wed, Oct 16, 2019 at 12:51 PM Eamon Heaney <address@hidden> wrote:
>> >
>> > Hi,
>> >
>> > I'm trying to get Bastib's gr-foo working on a raspberry pi. The OS is 
>> > Ubuntu Mate, freshly installed. I installed gnuradio with Pybombs, and 
>> > that's working fine, but when I try to "pybombs install uhd," it hangs 6% 
>> > of the way through "Building..."
>> >
>> > I interrupted it after it didn't budge for half an hour.
>> >
>> > Screenshot of the problem attached. Any idea why this is happening?
>> >
>> > --
>> > Eamon Heaney
>> > Fleet Commander
>> > President, Model UN at Virginia Tech
>> > _______________________________________________
>> > Discuss-gnuradio mailing list
>> > address@hidden
>> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>
>>
>>
>> --
>> GDB has a 'break' feature; why doesn't it have 'fix' too?
>
>
>
> --
> Eamon Heaney
> Fleet Commander
> President, Model UN at Virginia Tech



-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?