need help on bus error problem

need help on bus error problem

[Teresa Tao]

Hi there,

I am working on an real time video playback applicaion on a mips cpu. But after my video application play a while like 5 to 10 minutes, a bus error happened.

We add some debug meesage in the kernel, so we know that after the do_ade function inside the unalign.c, the bus error happens for the opcode lw or sw. So my guess is that I have an unaligned memory pointer(not in 4 byte boundary).
But my puzzle is that if I have an unaligned memory pointer, it should happen at the first loop I playback, how come it happens after it plays several loops?
Is there a possibility that my application's stack being trashed after a while? but I don't have recursive calls inside my application.


Thanks in advance!

Teresa

need help on bus error problem

[Teresa Tao]

Hi there,

I am working on an real time video playback applicaion on a mips cpu. But after my video application play a while like 5 to 10 minutes, a bus error happened.

We add some debug meesage in the kernel, so we know that after the do_ade function inside the unalign.c, the bus error happens for the opcode lw or sw. So my guess is that I have an unaligned memory pointer(not in 4 byte boundary).
But my puzzle is that if I have an unaligned memory pointer, it should happen at the first loop I playback, how come it happens after it plays several loops?
Is there a possibility that my application's stack being trashed after a while? but I don't have recursive calls inside my application.


Thanks in advance!

Teresa

Re: need help on bus error problem

[Jun Sun]

On Sat, Oct 25, 2003 at 09:44:35AM -0700, Teresa Tao wrote:
> Hi there,
> 
> I am working on an real time video playback applicaion on a mips cpu. But after my video application play a while like 5 to 10 minutes, a bus error happened.
> 
> We add some debug meesage in the kernel, so we know that after the do_ade function inside the unalign.c, the bus error happens for the opcode lw or sw. So my guess is that I have an unaligned memory pointer(not in 4 byte boundary).
> But my puzzle is that if I have an unaligned memory pointer, it should happen at the first loop I playback, how come it happens after it plays several loops?
> 

There are many reasons for having bus error, cache, errant pointers,
unstable hardware, or some tricky kernel bugs which happens when
certain conditions happen together.

> Is there a possibility that my application's stack being trashed after a while? but I don't have recursive calls inside my application.

Everything is possible.  :)

Jun