On 12/06/2017 03:06 PM, Yuanhan Liu wrote:
On Wed, Dec 06, 2017 at 12:23:19PM +0100, Maxime Coquelin wrote:
Hi,
On 12/05/2017 07:58 AM, Wang, Wei 5. (NSB - CN/Hangzhou) wrote:
Hi, all
In DPDK document, it it described that Virtio in containers Cannot work when
there are more than VHOST_MEMORY_MAX_NREGIONS(8) hugepages. In another word, do
not use 2MB hugepage so far. Do you know the reason of this limitation?
What document are you referring to?
Actually, a single region is composed of several hugepages, be it 1G or
2M. I use 2M hugepages daily without issues.
He was talking about virtio-user.
Ok, thanks for the correction.
The lookup time for every translation will be very costly if we have one
region per 2MB page.
--yliu
The limitation comes from the Vhost-user protocol spec. I know there are
discussions to enlarge it, but it would require a new protocol flag not
to break existing implementations, so no workaround possible.
In my envirionment, the pdpe1gb is not set in cpu flag, so hugepage can't be
set to 1GB size. The hugepage number shall be more than 8
So is there any solution or workaround to fix this limitation? Or change dpdk
code to fix this limitation?
Have you tried to use 2MB pages and faced the NREGIONS > 8 case?
If so, could you tell us more about your setup (QEMU version, VM RAM
size, etc...)?
Cheers,
Maxime
Vivian
seat: 19009
phone: 13738006921
