Re: [dpdk-dev] [PATCH] config: reduce memory requirements for DPDK

[Thomas Monjalon <thomas@monjalon.net>]

24/07/2018 13:04, Burakov, Anatoly:
> On 24-Jul-18 11:23 AM, Thomas Monjalon wrote:
> > 24/07/2018 12:03, Anatoly Burakov:
> >> It has been reported that current memory limitations do not work
> >> well on an 8-socket machines in default configuration when big
> >> page sizes are used [1].
> >>
> >> Fix it by reducing memory amount reserved by DPDK by default to
> >> 32G per page size per NUMA node. This translates to allowing us
> >> to reserve 32G per page size per NUMA node on 8 nodes with 2
> >> page sizes.
> >>
> >> [1] https://mails.dpdk.org/archives/dev/2018-July/108071.html
> >>
> >> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> >> ---
> >>
> >> Notes:
> >>      We could have increased CONFIG_RTE_MAX_MEM_MB but this would've
> >>      brought other potential problems due to increased memory
> >>      preallocation, and secondary process initialization is flaky
> >>      enough as it is. I am willing to bet that 32G per page size is
> >>      more than enough for the majority of use cases, and any
> >>      application with bigger requirements could adjust config options
> >>      itself.
> > [...]
> >> -CONFIG_RTE_MAX_MEMSEG_PER_TYPE=32768
> >> -CONFIG_RTE_MAX_MEM_MB_PER_TYPE=131072
> >> +CONFIG_RTE_MAX_MEMSEG_PER_TYPE=16384
> >> +CONFIG_RTE_MAX_MEM_MB_PER_TYPE=32768
> > 
> > Ideally, it should be a run-time option.
> > 
> 
> It can be, yes, and this can be worked on for next release. However, we 
> also need to have good default values that work across all supported 
> platforms.

Yes sure, we can wait the next release for a run-time option.

How can we be sure these default values are good enough?
It would be good to have several acks from various projects or companies.