Re: [dpdk-dev] Valgrind and DPDK - RDRAND + RTE_MACHINE obstacle

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

Hi Morten

I'm not that familiar with valgrind, but as far as I know it's using some kind of CPU emulation. Most likely the processor being emulated by valgrind doesn't have the capabilities your actual CPU has (sort of like trying to run a AVX2-compiled code on a QEMU machine emulating Westmere). You may try to edit the config file to change the RTE_MACHINE to compile DPDK for another platform.

Thanks,
Anatoly

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Morten Jagd Christensen
Sent: Wednesday, November 12, 2014 9:44 AM
To: dev@dpdk.org
Subject: Re: [dpdk-dev] Valgrind and DPDK - RDRAND + RTE_MACHINE obstacle

Hi all,

Thanks to Marc for sharinghis experiment and great to hear that others might benefit form the latest developments.

I can add the following experience:

Last night I downloaded Valgrind 3.10.0, applied the patch and built Valgrind  with success.

Unfortunately on my hardware (Xeon E5 processors) and dpdk-1.7.1 I now get the following error:

$ sudo /usr/local/valgrind/bin/valgrind ./build/myprogram -c 0xffff -n 4 ==24093== Memcheck, a memory error detector ==24093== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==24093== Using Valgrind-3.10.0 and LibVEX; rerun with -h for copyright info ==24093== Command: ./build/myprogram -c 0xffff -n 4 ==24093==
ERROR: This system does not support "RDRAND".
Please check that RTE_MACHINE is set correctly.

Has anyone experienced the same?

Cheers

Morten

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Marc Sune
Sent: 7. november 2014 04:36
To: Matthew Hall
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] Valgrind and DPDK - does it work ?

On 07/11/14 02:04, Matthew Hall wrote:
> On Fri, Nov 07, 2014 at 01:22:49AM +0100, Marc Sune wrote:
>> Found some time to have a close look. I also wanted to check a DPDK 
>> app against valgrind. It works!
>>
>> I downloaded and compiled valgrind from sources (3.10.0) and applied
>> (manually) this patch:
>>
>> https://bugs.kde.org/attachment.cgi?id=85950&action=edit
>>
>> (Applied around line 2216)
>>
>>  From this post:
>>
>> http://valgrind.10908.n7.nabble.com/mpich-unable-to-munmap-hugepages-
>> td49150.html
>>
>> Happy debugging
>> Marc
> Marc,
>
> This is just AMAZING!!! I have wished for it for many years for DPDK, 
> ever since I used it in beta before it went GA.
Thanks

Most kudos though (if not all), should go to T. Janjusic. I just found it and backported to the latest stable:

https://bugs.kde.org/show_bug.cgi?id=333051

>
> Would it be possible to post your modification of Valgrind in Github, 
> Bitbucket, or some other repo? I'd like to try this out on my app, too.

Sure, it is a good idea.

I just did a quick&dirty import of the latest stable release 3.10.0. No git-svn , or anything fancy (github import failed, silently ignoring
files...)  no gitignore too. And then I applied the patch:

https://github.com/bisdn/valgrind-hugepages

Please note the comment in README.md, I cannot provide any support or take any responsibility. We will also delete this repo once there is a stable release.

But you can at least try it, should work ;)

>
> Also, not sure if anybody sent this upstream to Valgrind, but if not, 
> we really should, so it just works by default from now on.
It already is, there is simply no stable release yet (see Phillipe comment):

https://bugs.kde.org/show_bug.cgi?id=333051#c8

Cheers
Marc
>
> Thanks,
> Matthew.