[dpdk-users] Basic hugepages question

[David Aldrich]

Thank you for your reply. I estimate the mbuf pools to be ~150MB. So would
a sensible hugepages configuration be 100 pages of 2MB each?


On Wed, Dec 9, 2020 at 5:00 PM Stephen Hemminger <stephen at networkplumber.org>
wrote:

> On Wed, 9 Dec 2020 16:34:29 +0000
> David Aldrich <david.aldrich.ntml at gmail.com> wrote:
>
> > Hi
> >
> > Having successfully demonstrated using dpdk with our application, it's
> been
> > pointed out to me that our settings are using a very large amount of
> memory.
> >
> > I am initialising the EAL with:
> >
> > -m 16000
> >
> > i.e. 16GB!
> >
> > However, I am only specifying a count of 0x4000 to rte_ring_create(),
> which
> > I call twice to create one Rx and one Tx ring. So I guess these are only
> > using 32MB RAM total.
> >
> > My questions are:
> >
> > 1) What would be a sensible amount of memory to specify with the '-m'
> > parameter to the EAL?
> > 2) What size / number of hugepages should I allocate in Linux?
> >
> > (I currently use boot parameters: 'hugepagesz=1G hugepages=20
> hugepagesz=2M
> > hugepages=0').
> >
> > Best regards
> > David
>
> For most DPDK applications the predominate user of huge pages is any
> mbuf pools you create.  You should be able to calculate the worst case size
> of all rings and mbuf pools and size your huge memory from that.
>