Re: Read corruption on ARM

[Jason Detring <detringj@xxxxxxxxx>]

On 2/26/13, Eric Sandeen <sandeen@xxxxxxxxxxx> wrote:
> On 2/26/13 3:58 PM, Jason Detring wrote:
>> Here's the kicker:  All this seems to happen only if xfs.ko is
>> crosscompiled with GCC 4.6 or 4.7.
>
> urk!  That is a kicker.
>
>> A module (just the module, the rest of kernel can be built with
>> anything) compiled with
>> cross-GCC 4.4.1, 4.5.4, or curiously 4.8 (20130224) has no issue at all.
>> I've kept an old 2009 Sourcery G++ (4.4.1) Lite toolchain around just
>> for building kernels.
>> I'd really like to retire it, but I'm a little afraid this is going to
>> recur in newer compilers.
>
> Maybe you can provide an xfs.ko built with each (for the same kernel)
> with debug info, and we can compare the disassembly?

OK, will do this evening when I can get things cleaned up a bit.


> Enabling the trace_xfs_da_btree_corrupt tracepoint might yield more
> info, can you do that?
>
> I think it's:
>
> # trace-cmd -e xfs_da_btree_corrupt &
> # <do your dir read>
> # fg
> # ^C (ctrl-c trace-cmd)
> # trace-cmd report
>
> We might get more info about the buffer in question that way.

I'll give it a go, but it might take me a while to get back to you.
I'm not familiar with that tool, and it looks like it's not part of my
base install.

> -Eric

Jason