[dpdk-dev] long initialization time for EAL init

[Burakov, Anatoly]

On 29-Jul-20 9:52 AM, David Marchand wrote:
> On Wed, Jul 29, 2020 at 10:51 AM Balaji K N <balaji.k.n at ericsson.com> wrote:
>> We are using OVS 2.12.0  with DPDK 18.11.2 release on Ubuntu 16.04 LTS. We do observe long initialization time for EAL init ( ~10 seconds for EAL memory initialization).
>>
>> Below is our hardware and memory configuration
>> Hardware                      : Dell Server
>> Sockets(NUMA)           : 2
>> CPUs                              : Each NUMA with 10 CPUs (Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz)
>> RAM                              : 128 GB
>> Hugepages reserverd : 2048 huge pages of 2MB and 100 Huge pages of 1G (reserved during boot time). We are using only 2MB huge pages for OVS process.
>> NIC                                  : Ethernet 10G 2P X520 ( ixgbe driver )
>>
>> Passing below EAL arguments with OVS process.
>> 2020-07-23T09:46:58.878Z|00014|dpdk|INFO|EAL ARGS: ovs-vswitchd -w 0000:04:00.0,support-multi-driver=1 -w 0000:42:00.0,support-multi-driver=1 -c 0x1 --huge-dir /mnt/huge_ovs_2M --socket-mem 2048,2048 --socket-limit 2048,2048.
>>
>> We debugged further in DPDK and found out that mmap called in eal_get_virtual_area is taking more time ( rte_eal_init->  rte_eal_memory_init -> rte_eal_memseg_init -> memseg_primary_init -> alloc_va_space -> eal_get_virtual_area ->mmap ). Long initialization time is noticeable difference compared to prior release. Any pointers would be helpful.
> 
> Did you try to start ovs with the --no-mlockall option?
> 
> 

That's most likely the culprit. I believe the recent mlock/MPROT changes 
are going to be backported to 18.11?

-- 
Thanks,
Anatoly