[LEDE-DEV] FW: UDP throughput caused kernel panic if configured bridge mode in /etc/config/network

[Y.B. Lu]

> -----Original Message-----
> From: Ben Greear [mailto:greearb at candelatech.com]
> Sent: Tuesday, April 25, 2017 12:03 AM
> To: Y.B. Lu; John Crispin; lede-dev at lists.infradead.org; jo at mein.io
> Cc: Wes Li; Xiaobo Xie
> Subject: Re: [LEDE-DEV] FW: UDP throughput caused kernel panic if
> configured bridge mode in /etc/config/network
> 
> On 04/24/2017 12:39 AM, Y.B. Lu wrote:
> > Hi John,
> >
> > Thank you very much.
> >
> > But I still feel it's strange the crash didn't happen if used brctl to
> configure instead of /etc/config/network.
> > Much memory(about 700MB) was consumed in UDP throughput test only when
> used /etc/config/network.
> >
> > As I know, both ls1043a with DPAA ethernet driver and ls1012a with ppfe
> ethernet driver had this issue.
> > I think maybe I should focus on deep studying in /etc/config/network.
> But we had a deadline by this month to resolve it.
> >
> > Is there any possibility the issue was caused by OpenWrt?
> > Thanks again.
> >
> >
> >
> > Best regards,
> > Yangbo Lu
> >
> >> -----Original Message-----
> >> From: John Crispin [mailto:john at phrozen.org]
> >> Sent: Monday, April 24, 2017 12:31 PM
> >> To: Y.B. Lu; lede-dev at lists.infradead.org; jo at mein.io
> >> Cc: Wes Li; Xiaobo Xie
> >> Subject: Re: [LEDE-DEV] FW: UDP throughput caused kernel panic if
> >> configured bridge mode in /etc/config/network
> >>
> >> Hi,
> >>
> >> this is most certainly a bug in the kernel. either the ethernet
> >> driver blows up under load or some other memory allocation related
> >> bug. it is very common for ethernet to kill boards under load by
> triggering bugs.
> >>
> >>      John
> >>
> >> On 24/04/17 05:49, Y.B. Lu wrote:
> >>> Hi John and Jo-Philipp,
> >>>
> >>> Have you ever got similar problem, or known any possible reason
> >>> about this, or known anyone who probably know this?
> >>>
> >>> I just found much memory would be consumed if I configured board as
> >>> bridge mode in /etc/config/network and did UDP throughput test.
> >>> But using brctl to configure bridge mode didn't consume memory.
> >>>
> >>> Thank you very much.
> >>>
> >>>
> >>> Best regards,
> >>> Yangbo Lu
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Y.B. Lu
> >>>> Sent: Thursday, April 13, 2017 1:24 PM
> >>>> To: 'lede-dev at lists.infradead.org'
> >>>> Subject: UDP throughput caused kernel panic if configured bridge
> >>>> mode in /etc/config/network
> >>>>
> >>>> Hi all,
> >>>>
> >>>> Recently I got below kernel panic when did UDP throughput test on
> >>>> NXP LS1043ARDB board. I configured the bridge mode in
> /etc/config/network.
> >>>> But if I used 'brctl' to configure the bridge mode, this issue
> >>>> would not happen.
> >>>> I also noticed almost all memory was consumed(about 700MB) when
> >>>> kernel crashed.
> >>>> Anyone have any idea about this?  Thank you very much.
> >>>>
> >>>> root at LEDE:/etc/fmc/config# [  263.981540] ksoftirqd/3: page
> >>>> allocation
> >>>> failure: order:0, mode:0x2080020 [  263.988339] CPU: 3 PID: 19 Comm:
> >>>> ksoftirqd/3 Not tainted 4.4.52 #0 [  263.994508] Hardware name:
> 
> This looks like just a warning...did the system really panic and stop
> working?
> 

[Lu Yangbo-B47093] Hi Ben, yes... The system crashed and reboot.
It's obvious that memory was consumed so much in the UDP throughput test with /etc/configs/network bridge mode setting. 
I ran a script to execute 'free' command every 0.5 sec to observe that.


> Thanks,
> Ben
> 
> 
> --
> Ben Greear <greearb at candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com