Re: PROBLEM: Kernel 2.6.10 crashing repeatedly and hard

[Herbert Poetzl <herbert@13thfloor.at>]

On Thu, Dec 30, 2004 at 02:23:01PM -0800, Linus Torvalds wrote:
> 
> 
> On Thu, 30 Dec 2004, Georg C. F. Greve wrote:
> > 
> >  lt> Any chance that you can get a full oops, with register info?
> >  lt> Right now your errors only have the call trace, not the registers
> >  lt> or the EIP itself..
> > 
> > Yes, for the first two times, the top of the crash report scrolled off
> > the screen and I don't have a serial console handy. The third crash
> > contained the 
> > 
> >  EFLAGS: 00010002   (2.6.10)
> >  EIP is at free_block+0x45/0xd0
> >  eax: 46484849   ebx: df2b1000   ecx: df2b1050   edx: df2ab000
> >  esi: c183cd80   edi: 00000001   ebp: 00000018   esp: c188fef8
> >  ds: 007b   es: 007b   ss: 0068
> >  Process events/0 (pid: 6, threadinfo:c188e000 task=c185ca20)
> >  Stack: c183cdb8 c1858810 c1858800 00000018 c183cd80 c0141724 c183cd80 c1858810
> >         00000018 c183ccb8 c183cd80 00000002 c183cce0 c01417c6 c183cd80 c1858800
> >         00000000 c183ccb8 c183ce10 00000003 c170fc20 c183b000 c170fc24 00000000
> > 
> > header, which I think may contain what you were looking for.
> 
> Ok. This is apparently a slab cache corruption issue.
> 
> Can you compile with SLAB_DEBUG and DEBUG_PAGEALLOC turned on, since that 
> may well catch something in the act (or it may make the machine so 
> unusably slow that it's not funny - who knows..)
> 
> > Meanwhile, because of the trouble, I gave Alans patch-2.6.10-ac1 a try
> > and again put ext3 on dm-crypt on raid5, and: No crash so far despite
> > moving and removing ~100 gigabytes a couple of times on to/from the
> > partition.
> 
> Goodie. Maybe Alan already knows what it's about. Alan? Any slab 
> corruption or wild pointers that you are aware of? However:
> 
> > I did however get occasional
> > 
> >  EXT3-fs error (device dm-0): ext3_readdir: bad entry in directory #37306376: directory entry across blocks - offset=0, inode=3350155169, rec_len=11148, name_len=1
> 
> I suspect that it's more of the slab corruption thing, and Alan's patch 
> ended up moving something around subtly enough that you don't get the 
> crash, but instead get corrupted buffer heads or similar.. Your BTTV 
> issues are interesting, though.

maybe this can provide more information (let me know if
you need an ASCII version, I'll transcribe it by hand then)

http://vserver.13thfloor.at/Experimental/OOPS/kernel-first-oops.jpg

(the kernel source tree might be still available)

best,
Herbert

> 		Linus
> -
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