When I searched for this problem, I found that almost no one else encountered such a problem.It's strange.By the way, I use dpdk-19.11.12 and Ubuntu-20.04

After looking at the dpdk source code, I know that the above code is in the rte_eth_dev_create function:

    if (priv_data_size) {
        ethdev->data->dev_private = **rte_zmalloc_socket**(
            name, priv_data_size, RTE_CACHE_LINE_SIZE,
            device->numa_node);

        if (!ethdev->data->dev_private) {
            RTE_LOG(ERR, EAL, "failed to allocate private data");
            retval = -ENOMEM;
            goto probe_failed;
        }
    }

It seems rte_zmalloc_socket return a NULL pointer. Why this happens?I allocated the relevant hugepage memory as requested.

Some Information：

EAL: Detected 4 NUMA nodes
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'PA'
EAL: No available hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
EAL: VFIO support initialized
EAL: PCI device 0000:31:00.0 on NUMA socket 3
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:31:00.1 on NUMA socket 3
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:51:00.0 on NUMA socket 5
EAL:   probe driver: 8086:10fb net_ixgbe
failed to allocate private data
EAL: Requested device 0000:51:00.0 cannot be used
EAL: PCI device 0000:51:00.1 on NUMA socket 5
EAL:   probe driver: 8086:10fb net_ixgbe
failed to allocate private data
EAL: Requested device 0000:51:00.1 cannot be used

Hugepages： (cat /proc/meminfo | grep Huge)

AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:      20
HugePages_Free:       19
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:    1048576 kB
Hugetlb:        20971520 kB

and mount information: (mount | grep huge)

cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=1024M)
nodev on /mnt/huge type hugetlbfs (rw,relatime,pagesize=1024M)

NIC:

Network devices using DPDK-compatible driver
============================================
0000:51:00.0 '82599ES 10-Gigabit SFI/SFP+ Network Connection 10fb' drv=igb_uio unused=ixgbe,vfio-pci
0000:51:00.1 '82599ES 10-Gigabit SFI/SFP+ Network Connection 10fb' drv=igb_uio unused=ixgbe,vfio-pci

Network devices using kernel driver
===================================
0000:31:00.0 'I350 Gigabit Network Connection 1521' if=enp49s0f0 drv=igb unused=igb_uio,vfio-pci 
0000:31:00.1 'I350 Gigabit Network Connection 1521' if=enp49s0f1 drv=igb unused=igb_uio,vfio-pci *Active*

Numa information:(numactl -H)

node 5 cpus: 30 31 32 33 34 35 78 79 80 81 82 83
node 5 size: 64475 MB
node 5 free: 58743 MB

82599ES NICs are on numa node 5.

I thought I did all the initialization but rte_eal_init returned the error "failed to allocate private data"

Any ideas on this issue? Thanks for help.

-----------------------update-----------------------------------------

Since this problem occurs in rte_zmalloc_socket(),I guess that there is something wrong with my configuration in Hugepages.But as posted above,i check Hugepages with command:

1.cat /proc/meminfo | grep Huge
2.mount | grep huge

first command checks available 1G Hugepages and second checks mount situation.

Result above seems to be normal which confuses me most.

Any clues?Thanks.

----------------------------update------------------------------------------

After using debug mode, I seem to find why this error occurs,but still got confused:

Pay attention to first parameter of rte_malloc_socket and rte_zmalloc_socket:

#0  rte_malloc_socket (type=0x17ffb0440 <error: Cannot access memory at address 0x17ffb0440>, size=93825001207904, align=96, socket_arg=2147157000) at ../lib/librte_eal/common/rte_malloc.c:46

#1  0x00007ffff7bdc79b in rte_zmalloc_socket (type=0x555555de3860 "0000:51:00.0", size=30552, align=64, socket=5) at ../lib/librte_eal/common/rte_malloc.c:79

#2  0x00007ffff7cebc08 in rte_eth_dev_create (device=0x555555ddcf50, name=0x555555de3860 "0000:51:00.0", priv_data_size=30552,  ethdev_bus_specific_init=0x7ffff59c74b5 <eth_dev_pci_specific_init>, bus_init_params=0x555555ddcf40, ethdev_init=0x7ffff59c8ed0 <eth_ixgbe_dev_init>,  init_params=0x0) at ../lib/librte_ethdev/rte_ethdev.c:4279

And in dpdk source code:

/*
* Allocate zero'd memory on specified heap.
*/
void *
rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket)
{
   void *ptr = rte_malloc_socket(type, size, align, socket);

   if (ptr != NULL)
       memset(ptr, 0, size);
   return ptr;
}

first parameter of rte_malloc_socket and rte_zmalloc_socket should be same, but as shown above, this does not happen in my case

other parameters seems to have same question!!

This confuses me, what appened?And is what happened above the cause of the error?

How can i fix it?Any clues?

It seems we need a dpdk developer's help:)

same question posted in stack overflow.

Thanks.