From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anjali Kulkarni <anjali-3r7Miqu9kMnR7s880joybQ@public.gmane.org>
Subject: Question on huge pages and running DPDK apps inside
	containers
Date: Thu, 3 Jul 2014 14:40:38 +0000
Message-ID: <CFDAB971.2ABC8%anjali@juniper.net>
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Hi,

I am encountering a problem running DPDK apps inside containers, and need y=
our help:

I create containers by doing:

lxc-create -t ubuntu -n fpc0
lxc-start -n fpc0

(Reserve hugepages and follow all other steps to run the DPDK app on host)

Then run a standard dpdk app, on host, it works fine, inside container, it =
runs into this problem:

ubuntu@fpc0:/dpdk/x86_64-default-linuxapp-gcc/app$ ./testpmd -c f -n 4 -- -=
i
rte_eal_init : 857
opt : 99
opt : 110
EAL: No free hugepages reported in hugepages-2048kB
PANIC in rte_eal_init():
Cannot get hugepage information
6: [./testpmd() [0x402941]]
5: [/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7f7f14f50ec5=
]]
4: [./testpmd() [0x40237e]]
3: [./testpmd() [0x478edb]]
2: [./testpmd() [0x4022ad]]
1: [./testpmd() [0x47e3c3]]
Aborted
ubuntu@fpc0:/dpdk/x86_64-default-linuxapp-gcc/app$

However, running this same app on the host, or doing lxc-execute works.

While trying to debug my own dpdk app, I see that reading the same file for=
 no of huge pages (

/sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages

 ), on the host, its value is read 2048, while inside the container it is 0=
. This is same file.
Also, if you cat the contents of this file, it is actually 0! (nr_hugepages=
 is 2048, but the DPDK code does not read this file.)

cat /sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages
0


In the below logs, the 2 prints "EAL: Using .." and "EAL: path ..." are add=
ed by me in DPDL eal library.

On host:
rte_eal_init : 859
opt : 99
opt : 110
EAL: Using free_hugepages
EAL: path /sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages
EAL: No of hugepages is 2048

Inside container:
pt : 99
opt : 110
EAL: Using free_hugepages
EAL: path /sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages
EAL: No of hugepages is 0


Has anyone run into this problem and know what's the issue?

Anjali