kern/144917: Flowtable crashes system

[Barney Cordoba]

--- On Fri, 4/2/10, K. Macy <kmacy at freebsd.org> wrote:

> From: K. Macy <kmacy at freebsd.org>
> Subject: Re: kern/144917: Flowtable crashes system
> To: "Ilya Zhuravlev" <ilya at el-crane.net>
> Cc: freebsd-net at freebsd.org, "Evgenii Davidov" <dado at korolev-net.ru>
> Date: Friday, April 2, 2010, 11:07 PM
> Please try with the latest 8-STABLE
> and tell me if recent changes fix it.
> 
> Thanks,
> Kip
> 
> On Thu, Mar 25, 2010 at 8:32 AM, Ilya Zhuravlev <ilya at el-crane.net>
> wrote:
> > On 21.03.2010 17:04, Evgenii Davidov wrote:
> >>
> >> Здравствуйте,
> >>
> >> On Sat, Mar 20, 2010 at 11:06:35PM +0000, Doychin
> Dokov пишет:
> >>
> >>>> Description:
> >>>
> >>> It seems like flowtable has been merged and
> enabled by default in 8.0....
> >>> which is a really really bad idea.
> >>> On a system which handles two full BGP tables
> it makes one of the CPU
> >>> cores run at 100% right after most of the
> prefixes get installed in the
> >>> routing table.
> >>
> >> i saw the same effect with ospf
> >>
> >
> > 8.0-p2, 2 full-view with openbgpd
> > "tuning":
> > net.inet.tcp.blackhole=2
> > net.inet.udp.blackhole=1
> > net.inet.icmp.icmplim_output=0
> > net.inet.icmp.drop_redirect=1
> > net.inet.flowtable.nmbflows=32768
> >
> > 1 week uptime.Now I think only about increasing tx/rx
> descriptors to reduce
> > interrupts (default values was not changed)
> >
> >
> > netstat -w1 -Iigb0
> >            input         (igb0)        
>   output
> >   packets  errs      bytes    packets  errs  
>    bytes colls
> >     49100     0   12290513      23693     0
>   27268884     0
> >     48322     0   12688283      24332     0
>   28099404     0
> >     50602     0   12759620      24437     0
>   27698341     0
> >     47857     0   11354124      21410     0
>   23845155     0
> >
> > netstat -w1 -Iigb1
> >            input         (igb1)        
>   output
> >   packets  errs      bytes    packets  errs  
>    bytes colls
> >     32428     0   35027019      24562     0
>    5624934     0
> >     30621     0   33384339      23569     0
>    4456944     0
> >     28419     0   31014269      21571     0
>    3638083     0
> >     29409     0   32524760      22137     0
>    3503600     0
> >     30965     0   33532742      23973     0
>    5089231     0
> >
> > netstat -w1 -Iem0
> >            input          (em0)        
>   output
> >   packets  errs      bytes    packets  errs  
>    bytes colls
> >     17217     0    3929366      72741     0
>   46377762     0
> >     17412     0    3745112      75522     0
>   49338883     0
> >     18385     0    4014568      77444     0
>   50532101     0
> >     17142     0    3875518      77125     0
>   47646681     0
> >     16870     0    3528316      73188     0
>   47940959     0
> >     17069     0    3682891      80268     0
>   52904747     0
> >     17313     0    4101576      75586     0
>   51933330     0
> > _______________________________________________
> > freebsd-net at freebsd.org


How about telling us how to turn it off; or better yet how to not
compile it into the kernel at all. Thats the best solution.

As my Dad used to say on a regular basis, we need this like we 
need a hole in our head. Is 8.0 the Kip Macy personal test bed?

Why is something that virtually no-one needs enabled by default?

Barney