Re: "Exception at ..." with 2.1.9 and 2.1.10 kernels

Alan Cox (
Mon, 25 Nov 1996 00:03:36 +0000 (GMT)

> I suspect the point is to use it as a debugging device to find
> unaligned accesses in the kernel (that aren't portable to RISC
> architectures). Don't enable it in user space, though -- legitimate
> programs will break.

The aligment traps are unbelievably useful in user space if we put them
in. Yes it needs you to add a piece of code to the program (crtalign.o
anyone). But it can tell you what kind of badly aligned operations you
are doing, and give you a dump to study.

There are a couple of other profiling items that would be nice to have
visible via user space. Tracing both page faults and TLB misses.