Re: [BUG] alignment problem in net/core/flow.c:flow_key_compare

[Måns Rullgård]

mru@xxxxxx (Måns Rullgård) writes:

> There is a problem with alignment in the flow_key_compare function in
> net/core/flow.c.  It takes arguments of type struct flowi * and casts
> them to flow_compare_t *, which is 64 bits on 64-bit machines.  It
> then proceeds to read and compare 64-bit values from these pointers.
> The problem is that struct flowi only requires 32-bit alignment, so
> these reads cause numerous unaligned exceptions.  On average, I get
> nearly 1000 unaligned exceptions per second.
>
> The solutions I see are either to force the alignment of struct flowi
> to 64 bits, or to use 32-bit access in flow_key_compare.

I forgot to mention that this is kernel 2.6.4.

-- 
Måns Rullgård
mru@xxxxxx

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/