[dpdk-dev] Big spike in DPDK VSZ

[Burakov, Anatoly]

On 02-Feb-20 9:22 AM, David Marchand wrote:
> On Thu, Jan 30, 2020 at 8:48 AM siddarth rai <siddsr at gmail.com> wrote:
>>
>> Hi,
>>
>> I have been using DPDK 19.08 and I notice the process VSZ is huge.
>>
>> I tried running the test PMD. It takes 64G VSZ and if I use the
>> '--in-memory' option it takes up to 188G.
>>
>> Is there anyway to disable allocation of such huge VSZ in DPDK ?
>> This is resulting in huge core files and I suspect that the problem will
>> compound on multi-NUMA machines.
> 
> For this particular issue, it might be interesting to look at madvise stuff:
> 
>         MADV_DONTDUMP (since Linux 3.4)
>                Exclude from a core dump those pages in the range
> specified by addr and length.  This is useful in applications that
> have large areas of memory that are known not to be useful in a core
> dump.
>                The effect of MADV_DONTDUMP takes precedence over the
> bit mask that is set via the /proc/PID/coredump_filter file (see
> core(5)).
> 
> (FreeBSD seems to have a MADV_NOCORE flag too).
> 
> 

This is perhaps the best option, as this problem isn't going away any 
time soon. We've had this problem on FreeBSD already, which is why 
--no-mlockall exists in testpmd and is default on FreeBSD, and which is 
why we advise all our validation teams to disable core dumping on 
FreeBSD when running DPDK. If a similar (but perhaps less invasive) 
solution exists for Linux, that's great.

-- 
Thanks,
Anatoly