Panic in bus_dmamap_load_mbuf (pmap.h:201)

[Cédric Jonas]

On Sun, 3 Jul 2005 22:56:33 +0200
Cédric Jonas <cedric at virtual-globe.net> wrote:

> Hello,
> 
> Since 1 or 2 months, I experienced panics when I use the ath interface of our server (configured as hostap). Also, the system hangs often (without panic) during the boot process at the "Setting hostname: icarus." level. Because I had absolutely no time, I couldn't learn to use the kernel debugger before. 
> 
> 
> 
> 	icarus# uname -a
> 	FreeBSD icarus 5.4-STABLE FreeBSD 5.4-STABLE #0: Sun Jul  3 15:14:13 CEST 2005     cedric at icarus:/usr/obj/usr/src/sys/ICARUS  i386
> 
> Sources are from July, 1
> 
> 
> 	debug.mpsafenet: 1
> 
> 
> 
> After compiling the kernel with debug options, I get the following during the boot process:
> 
> 	Setting hostname: icarus.
> 	lock order reversal
> 	 1st 0xc2cd4c6c ath0 (network driver) @ /usr/src/sys/dev/ath/if_ath.c:893
> 	 2nd 0xc30583c8 user map (user map) @ /usr/src/sys/vm/vm_map.c:2998
> 
>
> Another important detail could be that I use a dual Xeon box, which HT enabled, which results in 4 logical CPU's and explain why anybody reported this problem before?!
> 
> I hope somebody could help, if you need additional informations, let me know.
> Thank you.
> 
> -- 
> Best regards, 
>  Cédric Jonas
> _______________________________________________
> freebsd-hackers at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe at freebsd.org"
> 


If it can help: I tried to disable PREEMPTION, the hyperthreading functionality (=> 2 logical CPU), and I set debug.mpsafenet to 0, but the LOR (+ Panic when ath0 is used) continue to occure...
I tried also to downgrade to 5.3-RELEASE, where the problems do _not_ occur... but that's not a solution.

-- 
Best regards, 
 Cédric Jonas