Re: [dpdk-users] qos_sched in DPDK 17.11.0 fails to initialize mbuf pool

[Ian Trick <ian.trick@multapplied.net>]

On 2017-11-17 04:19 AM, Dumitrescu, Cristian wrote:
> 
> 
>> -----Original Message-----
>> From: Ian Trick [mailto:ian.trick@multapplied.net]
>> Sent: Friday, November 17, 2017 1:24 AM
>> To: users@dpdk.org
>> Cc: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
>> Subject: qos_sched in DPDK 17.11.0 fails to initialize mbuf pool
>>
>> Hi. I'm having an issue starting the qos_sched example program.
>>
>> # ./examples/qos_sched/build/qos_sched --no-huge -l 1,2,3 --vdev
>> net_af_packet0,iface=eth1 -- --pfc "0,0,2,3" --cfg
>> examples/qos_sched/profile_ov.cfg
>>
>> EAL: Detected 16 lcore(s)
>> EAL: Probing VFIO support...
>> EAL: Started without hugepages support, physical addresses not available
>> EAL: PCI device 0000:08:00.0 on NUMA socket -1
>> EAL:   Invalid NUMA socket, default to 0
>> EAL:   probe driver: 8086:10d3 net_e1000_em
>> PMD: Initializing pmd_af_packet for net_af_packet0
>> PMD: net_af_packet0: AF_PACKET MMAP parameters:
>> PMD: net_af_packet0:    block size 4096
>> PMD: net_af_packet0:    block count 256
>> PMD: net_af_packet0:    frame size 2048
>> PMD: net_af_packet0:    frame count 512
>> PMD: net_af_packet0: creating AF_PACKET-backed ethdev on numa socket 0
>> EAL: Error - exiting with code: 1
>>   Cause: Cannot init mbuf pool for socket 0
>>
> 
> Personally I never used this application with --no-huge or with AF_PACKET, so I suggest you start from the configuration known to work (as detailed in the Sample App Guide) and then change/add one variable at a time to see which change triggers the mempool issue.
> 
> This app needs large amounts of memory for the mempool, as traffic management is buffering lots of packets in lots of queues. Out typical tests are done with 4K pipes/output port (64K queues/output port) so we provision mempool to have 2M buffers for each output port. The size of the mempool is hardcoded in the application. 

Can I configure this to run with fewer queues or something so that it
requires less memory. I thought running with profile_ov.cfg might have
lower memory requirements since it includes:
> number of pipes per subport = 32
compared to 4096 in the other configuration file. So I figured there
would be fewer queues and buffers? But I only have 4GB available on the
device I have if I want to test something that isn't AF_PACKET.

> 
>>
>> This is version 17.11.0 from the repo. My RTE_TARGET is
>> x86_64-native-linuxapp-clang. eth1 is a veth. I've tried running with
>> `-m` and using a low value but the issue still happens.
>>
>> From what I can tell, rte_pktmbuf_pool_create() is failing and rte_errno
>> is set to EINVAL.
>>
>> In librte_mempool/rte_mempool.c, the function
>> rte_mempool_populate_virt() is succeeding this test and returning -EINVAL:
>>
>> 	if (RTE_ALIGN_CEIL(len, pg_sz) != len)
>> 		return -EINVAL;
>>
>> In that context, len is mz->len, the length of a memzone passed by the
>> caller, rte_mempool_populate_default(). Which got it here:
>>
>> 	mz = rte_memzone_reserve_aligned(mz_name, size,
>> 		mp->socket_id, mz_flags, align);
>> 	/* not enough memory, retry with the biggest zone we have */
>> 	if (mz == NULL)
>> 		mz = rte_memzone_reserve_aligned(mz_name, 0,
>> 			mp->socket_id, mz_flags, align);
>>
>> This fails the first call, and succeeds the second when it passes 0 as
>> the size. memzone_reserve_aligned_thread_unsafe(), in
>> librte_eal/common/eal_common_memzone.c, gets the length this way:
>>
>> 	requested_len = find_heap_max_free_elem(&socket_id, align);
>>
>> So the align value is 4096. But the value returned by
>> find_heap_max_free_elem() isn't aligned to that -- I think? Since it
>> fails the check later on.
>>
>> I'm not sure if this is a thing with my environment where I don't have
>> enough memory? (Although I would have expected a different error for
>> that.) Or I don't have the right program arguments? Or one of these
>> functions isn't doing what it's supposed to?