Re: Huge memory leak with 4.15.0-rc2+

On 12/12/2017 09:57 AM, Paweł Staszewski wrote:

W dniu 2017-12-11 o 23:27, Paweł Staszewski pisze:

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W dniu 2017-12-11 o 23:15, John Fastabend pisze:

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On 12/11/2017 01:48 PM, Paweł Staszewski wrote:

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W dniu 2017-12-11 o 22:23, Paweł Staszewski pisze:

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Hi


I just upgraded some testing host to 4.15.0-rc2+ kernel

And after some time of traffic processing - when traffic on all ports
reach about 3Mpps - memleak started.

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Some observations - when i disable tso on all cards there is more
memleak.

When traffic starts to drop - there is less and less memleak
below link to memory usage graph:
https://ibb.co/hU97kG

And there is rising slab_unrecl - Amount of unreclaimable memory used
for slab kernel allocations


Forgot to add that im using hfsc and qdiscs like pfifo on classes.

Maybe some error case I missed in the qdisc patches I'm looking into
it.

Thanks,
John

This is how it looks like when corelated on graph - traffic vs mem
https://ibb.co/njpkqG

Typical hfsc class + qdisc:
### Client interface vlan1616
tc qdisc del dev vlan1616 root
tc qdisc add dev vlan1616 handle 1: root hfsc default 100
tc class add dev vlan1616 parent 1: classid 1:100 hfsc ls m2 200Mbit ul m2 200Mbit
tc qdisc add dev vlan1616 parent 1:100 handle 100: pfifo limit 128
### End TM for client interface
tc qdisc del dev vlan1616 ingress
tc qdisc add dev vlan1616 handle ffff: ingress
tc filter add dev vlan1616 parent ffff: protocol ip prio 50 u32 match ip src 0.0.0.0/0 police rate 200Mbit burst 200M mtu 32k drop flowid 1:1

And this is same for about 450 vlan interfaces


Good thing is that compared to 4.14.3 i have about 5% less cpu load on 4.15.0-rc2+

When hfsc will be lockless or tbf - then it will be really huge difference in cpu load on x86 when using traffic shaping - so really good job John.

Yestarday changed kernel from
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git

to

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?h=v4.15-rc3


And there is no memleak.
So yes probabbly lockless qdisc patches

It seems I was able to produce a similar memleak with qdisc patches
reverted and running TCP traffic overnight. I guess we can do a bisect
and track it down. Will try to get a "good" run tonight.

Thanks,
John