[dpdk-dev] CONFIG_RTE_MAX_MEM_MB fails in DPDK18.05

[Kevin Traynor]

On 19/02/2020 10:23, Burakov, Anatoly wrote:
> On 17-Feb-20 9:57 AM, Kamaraj P wrote:
>> Hi Anatoly,
>> Thanks for the clarifications.
>>
>> Currently we are migrating to the new DPDK 18.11 ( from 17.05).  Here is 
>> our configuration:
>> =======================================================================
>> We have configured the "--legacy-mem" option and changed the 
>> CONFIG_RTE_MAX_MEM_MB to 2048 (and we are passing 2MB huge page 188 and 
>> no 1G hugepages in the bootargs).
>> Our application deployment as 2G RAM
>> =======================================================================
>> We are observing the hang issue, with above configuration.
>> Please see the below logs:
>> EAL: Detected lcore 0 as core 0 on socket 0
>> EAL: Support maximum 128 logical core(s) by configuration.
>> EAL: Detected 1 lcore(s)
>> EAL: Detected 1 NUMA nodes
>> EAL: open shared lib /usr/lib64/librte_pmd_ixgbe.so.2.1
>> EAL: open shared lib /usr/lib64/librte_pmd_e1000.so.1.1
>> EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
>> EAL: Module /sys/module/vfio_pci not found! error 2 (No such file or 
>> directory)
>> EAL: VFIO PCI modules not loaded
>> EAL: No free hugepages reported in hugepages-1048576kB
>> EAL: No free hugepages reported in hugepages-1048576kB
>> EAL: Probing VFIO support...
>> EAL: Module /sys/module/vfio not found! error 2 (No such file or directory)
>> EAL: VFIO modules not loaded, skipping VFIO support...
>> EAL: Ask a virtual area of 0x2e000 bytes
>> EAL: Virtual area found at 0x100000000 (size = 0x2e000)
>> EAL: Setting up physically contiguous memory...
>> EAL: Setting maximum number of open files to 4096
>> EAL: Detected memory type: socket_id:0 hugepage_sz:1073741824
>> EAL: Detected memory type: socket_id:0 hugepage_sz:2097152
>> EAL: Creating 1 segment lists: n_segs:1 socket_id:0 hugepage_sz:1073741824
>> EAL: Ask a virtual area of 0x1000 bytes
>> EAL: Virtual area found at 0x10002e000 (size = 0x1000)
>> EAL: Memseg list allocated: 0x100000kB at socket 0
>> EAL: Ask a virtual area of 0x40000000 bytes
>> <<< --- struck here ---> >>>>
>>
>>
>> Is there any other dpdk options thro which we can resolve the above 
>> issue ? Any thoughts ?
>> Like passing the *--socket-limit* and *--m *parameter etc during the EAL 
>> Init (could help ???).
>> Please suggest us.
>>
> 
> It sounds like it hangs in eal_get_virtual_area() - we've had a similar 
> issue before, not sure if the fix was backported to 18.11. Is this patch 
> present in your code?
> 
> http://patches.dpdk.org/patch/51943/
> 

In 18.11 LTS releases since v18.11.2. Current release is v18.11.6.

commit 558509fbb2b0a0f5803f348634e4956ff8cb5214
Author: Shahaf Shuler <shahafs at mellanox.com>
Date:   Sun Mar 31 11:43:48 2019 +0300

    mem: limit use of address hint

    [ upstream commit 237060c4ad15b4ee9002be3c0e56ac3070eceb48 ]

> If not, it would be of great help if you could find the exact spot where 
> the hang happens.
>