On 27.03.2017 16:01, Sergio Gonzalez Monroy wrote:
> On 09/03/2017 12:57, Ilya Maximets wrote:
>> On 08.03.2017 16:46, Sergio Gonzalez Monroy wrote:
>>> Hi Ilya,
>>>
>>> I have done similar tests and as you already pointed out, 'numactl
>>> --interleave' does not seem to work as expected.
>>> I have also checked that the issue can be reproduced with quota limit on
>>> hugetlbfs mount point.
>>>
>>> I would be inclined towards *adding libnuma as dependency* to DPDK to make
>>> memory allocation a bit more reliable.
>>>
>>> Currently at a high level regarding hugepages per numa node:
>>> 1) Try to map all free hugepages. The total number of mapped hugepages
>>> depends if there were any limits, such as cgroups or quota in mount point.
>>> 2) Find out numa node of each hugepage.
>>> 3) Check if we have enough hugepages for requested memory in each numa
>>> socket/node.
>>>
>>> Using libnuma we could try to allocate hugepages per numa:
>>> 1) Try to map as many hugepages from numa 0.
>>> 2) Check if we have enough hugepages for requested memory in numa 0.
>>> 3) Try to map as many hugepages from numa 1.
>>> 4) Check if we have enough hugepages for requested memory in numa 1.
>>>
>>> This approach would improve failing scenarios caused by limits but It would
>>> still not fix issues regarding non-contiguous hugepages (worst case each
>>> hugepage is a memseg).
>>> The non-contiguous hugepages issues are not as critical now that mempools
>>> can span over multiple memsegs/hugepages, but it is still a problem for any
>>> other library requiring big chunks of memory.
>>>
>>> Potentially if we were to add an option such as 'iommu-only' when all
>>> devices are bound to vfio-pci, we could have a reliable way to allocate
>>> hugepages by just requesting the number of pages from each numa.
>>>
>>> Thoughts?
>> Hi Sergio,
>>
>> Thanks for your attention to this.
>>
>> For now, as we have some issues with non-contiguous
>> hugepages, I'm thinking about following hybrid schema:
>> 1) Allocate essential hugepages:
>> 1.1) Allocate as many hugepages from numa N to
>> only fit requested memory for this numa.
>> 1.2) repeat 1.1 for all numa nodes.
>> 2) Try to map all remaining free hugepages in a round-robin
>> fashion like in this patch.
>> 3) Sort pages and choose the most suitable.
>>
>> This solution should decrease number of issues connected with
>> non-contiguous memory.
>
> Sorry for late reply, I was hoping for more comments from the community.
>
> IMHO this should be default behavior, which means no config option and
> libnuma as EAL dependency.
> I think your proposal is good, could you consider implementing such approach
> on next release?
Sure, I can implement this for 17.08 release.
>>
>>> On 06/03/2017 09:34, Ilya Maximets wrote:
>>>> Hi all.
>>>>
>>>> So, what about this change?
>>>>
>>>> Best regards, Ilya Maximets.
>>>>
>>>> On 16.02.2017 16:01, Ilya Maximets wrote:
>>>>> Currently EAL allocates hugepages one by one not paying
>>>>> attention from which NUMA node allocation was done.
>>>>>
>>>>> Such behaviour leads to allocation failure if number of
>>>>> available hugepages for application limited by cgroups
>>>>> or hugetlbfs and memory requested not only from the first
>>>>> socket.
>>>>>
>>>>> Example:
>>>>> # 90 x 1GB hugepages availavle in a system
>>>>>
>>>>> cgcreate -g hugetlb:/test
>>>>> # Limit to 32GB of hugepages
>>>>> cgset -r hugetlb.1GB.limit_in_bytes=34359738368 test
>>>>> # Request 4GB from each of 2 sockets
>>>>> cgexec -g hugetlb:test testpmd --socket-mem=4096,4096 ...
>>>>>
>>>>> EAL: SIGBUS: Cannot mmap more hugepages of size 1024 MB
>>>>> EAL: 32 not 90 hugepages of size 1024 MB allocated
>>>>> EAL: Not enough memory available on socket 1!
>>>>> Requested: 4096MB, available: 0MB
>>>>> PANIC in rte_eal_init():
>>>>> Cannot init memory
>>>>>
>>>>> This happens beacause all allocated pages are
>>>>> on socket 0.
>>>>>
>>>>> Fix this issue by setting mempolicy MPOL_PREFERRED for each
>>>>> hugepage to one of requested nodes in a round-robin fashion.
>>>>> In this case all allocated pages will be fairly distributed
>>>>> between all requested nodes.
>>>>>
>>>>> New config option RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES
>>>>> introduced and disabled by default because of external
>>>>> dependency from libnuma.
>>>>>
>>>>> Cc:<sta...@dpdk.org>
>>>>> Fixes: 77988fc08dc5 ("mem: fix allocating all free hugepages")
>>>>>
>>>>> Signed-off-by: Ilya Maximets<i.maxim...@samsung.com>
>>>>> ---
>>>>> config/common_base | 1 +
>>>>> lib/librte_eal/Makefile | 4 ++
>>>>> lib/librte_eal/linuxapp/eal/eal_memory.c | 66
>>>>> ++++++++++++++++++++++++++++++++
>>>>> mk/rte.app.mk | 3 ++
>>>>> 4 files changed, 74 insertions(+)
>
> Acked-by: Sergio Gonzalez Monroy <sergio.gonzalez.mon...@intel.com>
Thanks.
Best regards, Ilya Maximets.
