Re: [dpdk-users] Run testpmd application and encountered no free page issues

[Shreyansh Jain <shreyansh.jain@nxp.com>]

Hi Paul,

Inline, with [SJ02]

From: Paul Tsvika [mailto:mozloverinweb@gmail.com] 
Sent: Wednesday, June 21, 2017 8:47 AM
To: Shreyansh Jain <shreyansh.jain@nxp.com>
Cc: users@dpdk.org
Subject: Re: [dpdk-users] Run testpmd application and encountered no free page issues

Thanks Shreyansh.

My comment prepended with [P01]


2017-06-20 19:10 GMT+08:00 Shreyansh Jain <mailto:shreyansh.jain@nxp.com>:
Hello Paul,

Some comments inline, prepended with [SJ01]:
(Would it be possible for you to send text mails to this mailing list - it helps in keeping replies contextual)

From: Paul Tsvika [mailto:mailto:mozloverinweb@gmail.com]
Sent: Tuesday, June 20, 2017 2:27 PM
To: Shreyansh Jain <mailto:shreyansh.jain@nxp.com>
Cc: mailto:users@dpdk.org
Subject: Re: [dpdk-users] Run testpmd application and encountered no free page issues

Hi Shreyansh,

Thanks for the reply.

By using the set-up script in DPDK:

the hugepage memory looks to be allocated properly:

cat /proc/meminfo

HugePages_Total:     240
HugePages_Free:     240
HugePages_Rsvd:        0
HugePages_Surp:         0
Hugepagesize:       2048 kB


and then i run the commands below in sequence:

$ sudo modprobe uio
$ sudo insmod ./build/kmod/igb_uio.ko
$ sudo ./usertools/dpdk-devbind.py -b igb_uio xxx:xx.0 xxx:xx.1   ( xxx.xx.0, xxx.xx.1 <-- 10G port pci address )
$ sudo ./build/app/testpmd -l 1,2,3 -n 2 -- -i

EAL: Detected 16 lcore(s)
EAL: No free hugepages reported in hugepages-1048576kB

[SJ01] DPDK iterates over all directories in /sys/kernel/mm/hugepages which contains one directory for each supported hugepage size. This log above is appearing because nothing was found for a directory named "hugepages-1048576kB". That is probably because you have '0' hugepages of size 1G in your system. This should not impact you until you are were expecting 1G hugepage size.

EAL: Probing VFIO support...
EAL: VFIO support initialized
EAL: PCI device 0000:03:00.0 on NUMA socket 0
EAL:   probe driver: 8086:15ad net_ixgbe
EAL: PCI device 0000:03:00.1 on NUMA socket 0
EAL:   probe driver: 8086:15ad net_ixgbe
EAL: PCI device 0000:05:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:05:00.1 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
Interactive-mode selected
USER1: create a new mbuf pool <mbuf_pool_socket_0>: n=163456, size=2176, socket=0
Configuring Port 0 (socket 0)
PMD: ixgbe_dev_link_status_print():  Port 0: Link Down
Port 0: 00:25:90:5C:E9:58
Configuring Port 1 (socket 0)
PMD: ixgbe_dev_link_status_print():  Port 1: Link Down
Port 1: 00:25:90:5C:E9:59
Checking link statuses...
Done
testpmd> 


Questions below:

1. It looks like the application can enter the interactive mode. however, I have no idea why EAL: No free hugepages reported in hugepages-1048576kB keeps popping out.

[SJ01] Lets ignore that for while. You have about 240 pages of 2M = ~480Mb. Application is demanding ~339Mb (n=163456, size=2176)


2. Is there any reason why the ports went down why I run the commands? The Link was up before running it.

[SJ01] This I am not sure. If the links were up _before_, they should be up now as well. Just out of curiosity, how did you check that links were up before? These links are not assigned to Linux kernel and are not visible in the ifconfig list.

[P01] I don't know why you mentioned that these links are not assigned to Linux kernel and not visible in the ifconfig list. ixgbe is the inbox driver of the kernel and eno3 and eno4 ( 10G ports ) appear in ifconfig list.
However, eno3 and eno4 gone away ( disappeared in ifconfig ) when running this command. I am still investigating the issue.  

[SJ02] That is not an issue. That is how it is supposed to work. When you start DPDK, it would unlink the devices from their standard ixgbe kernel module driver and link to uio/vfio driver for direct userspace interaction. That is the reason these links would not appear in ifconfig list – and that is the right way. Were you able to use these links when they were bound to ixgbe kernel module - that is, ping worked before DPDK was started? 



3. The hugepage will be gone after running this application.

HugePages_Total:     240
HugePages_Free:         0
HugePages_Rsvd:        0
HugePages_Surp:         0
Hugepagesize:       2048 kB

It became this. However, how can i free it again ? I tried to umount and mount again but it did not work.

[SJ01] Just go and delete all files created in /mnt/hugepages/ folder. You would have "HugePages_Free" available again. But, only if you have the application stopped.


Please advice if any.

[SJ01] Above is all what I know. I have no idea why your links are appearing down.

-
Shreyansh




Paul
-- 
P.T