On 23/03/2017 16:24, Ruslan Bilovol wrote:
On 03/22/2017 02:08 PM, Ruslan Bilovol wrote:
On 03/21/2017 04:41 PM, Sergio Gonzalez Monroy wrote:
The DPDK will still try to allocate contiguous hugepages.
Since DPDK v16.07 the mempool library is able to create a mempool
with multiple chunks of memory.
You would still have the contig memory restriction for any other
DPDK library or app.
Another question: are there any improvements in contiguous hugepages
requirements in latest DPDK (v17.02)?
Not that I can think of.
Sergio
Thanks,
Ruslan
Are you pre-allocating hugepages on boot (kernel cmdline) or runtime?
I tried both cases, and there is no much difference between them.
(I used debug prints in kernel to see physical address of
preallocated hugepages
Main issue is that linux kernel memory allocation algorithm was changed
with "fair zone allocator policy" commits, and in my case need to
pre-allocate 2x or even 3x more hugepages now.
Regards,
Ruslan
Sergio
On 21/03/2017 14:20, Ruslan Bilovol wrote:
Hi,
Recently after moving to 4.4 Linux kernel we found that DPDK v16.07
can't find physically contiguous chunk of hugepages memory.
I've tracked this down to kernel commits
81c0a2bb515f ("mm: page_alloc: fair zone allocator policy")
fff4068cba48 ("mm: page_alloc: revert NUMA aspect of fair
allocation policy")
4ffeaf3560a5 ("mm: page_alloc: reduce cost of the fair zone
allocation policy")
These commits changed default page allocator behavior so it now
allocates
memory proportionally from preferred and lower zones. Hugepages
are scattered proportionally among few memory zones, so possibility
to find big physically contiguous chunk of hugepages memory is much
lower.
I see that there were some attempts to move from contiguous hugepages
approach, like http://dpdk.org/ml/archives/dev/2016-March/035201.html
Also some discussion here:
http://dpdk.org/ml/archives/users/2016-October/001050.html
The question: is contiguous hugepages memory still required in
latest DPDKs,
and if not, since which version?
Thanks,
Ruslan
