Date: Sun, 21 Jul 2002 21:22:23 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Marc Recht <marc@informatik.uni-bremen.de> Cc: current@FreeBSD.ORG Subject: Re: mysterious dead-locks with system ssh Message-ID: <20020721212223.A62379@panzer.kdm.org> In-Reply-To: <20020721222955.7658986f.marc@informatik.uni-bremen.de>; from marc@informatik.uni-bremen.de on Sun, Jul 21, 2002 at 10:29:55PM %2B0200 References: <1026680887.757.9.camel@leeloo.intern.geht.de> <20020721222955.7658986f.marc@informatik.uni-bremen.de>
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On Sun, Jul 21, 2002 at 22:29:55 +0200, Marc Recht wrote: > > I'm getting strange dead-locks/complete lookups when I use the system > > ssh with port forwarding. Using something like: > > ssh -L8080:remote:8080 account@remote > > to forward a remote apache to my local box. When I access > > http://localhost:8080/ not later than the third click on link (or > > pressing reload) my box locks up completely. I don't even get into the > > debugger or get a crash dump. The box is just plain dead. Though > > "normal" SSH works perfectly and accessing a local (not forwarded) > > apache works, too. The world and kernel is of today and IIRC this > > actually did work last week (or the week before). > I've found the reason for this dead-lock. I had turned ZERO_COPY_SOCKETS on. > ESound/zero_copy_sockets causes the same dead-lock... Hmm, nothing has changed in the zero copy code, although lots of things are changing in the VM code and elsewhere in the kernel. Can you track down whether the problem is with zero copy send or receive? To figure this out, try disabling zero copy send and receive individually: sysctl -w kern.ipc.zero_copy.send=0 sysctl -w kern.ipc.zero_copy.receive=1 then sysctl -w kern.ipc.zero_copy.send=1 sysctl -w kern.ipc.zero_copy.receive=0 That'll help isolate the problem somewhat. It's also possible that it only happens with both turned on. Also, what sort of network interfaces do you have on your machine? What is the MTU? Are you running with SMP or not, and is WITNESS turned on or not? Would you be able to try a binary search to try to figure out where things broke for you? Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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