Re: CAKE and r8169 cause panic on upload in v4.19

[Heiner Kallweit]

On 26.10.2018 22:54, Oleksandr Natalenko wrote:
> Hi.
> 
> On 26.10.2018 22:25, Dave Taht wrote:
>> Can you repeat your test, disabling gro splitting in cake?
>>
>> the option is "no-split-gso"
> 
> Still panics. Takes a couple of rounds, but panics.
> 
> Moreover, I've stressed my HTB setup like this too for a longer time, and it panics as well. So, at least, now I have a proof this is not a CAKE-specific thing.
> 
> Also, I've stressed it even with noqueue, and the panic is still there. So, this thing is not even sch-specific.
> 
> Next, I've seen GRO bits in the call trace and decided to disable GRO on this NIC. So far, I cannot trigger a panic with GRO disabled even after 20 rounds of speedtest.
> 
> So, must be some generic thing indeed.
> 
In net-next there's the following patch which mentions in the
description that it "eliminates spurious list pointer poisoning":
992cba7e276d ("net: Add and use skb_list_del_init().") 
And spurious list pointer poisoning is what we see here (IMO).

As an idea this patch and a8305bff6852 ("net: Add and use skb_mark_not_on_list().")
from net-next could be applied on top of 4.19. Would be curious
whether it fixes the issue.