Re: [PATCH 11/12] perf lock: New subcommand "perf lock", for analyzinglock statistics

[Hitoshi Mitake]

On 2010å01æ22æ 22:39, Hitoshi Mitake wrote:

Hi Ingo,
I have a trivial but difficult problem on this 11th patch.

> +static void
> +process_lock_acquire_event(void *data,
> +			   struct event *event __used,
> +			   int cpu __used,
> +			   u64 timestamp __used,
> +			   struct thread *thread __used)
> +{
> +	struct trace_acquire_event acquire_event;
> +	u64 tmp;		/* this is required for casting... */
> +
> +	tmp = raw_field_value(event, "lockdep_addr", data);
> +	acquire_event.addr = (void *)tmp;   # <- type of addr is void *

In the above function,
the statement:
    raw_field_value(event, "lockdep_addr", data);
reads member of event which is type of void *.

But, direct assigning like
    acquire_event.addr = (void *)raw_field_value(event, "lockdep_addr", 
data);
produces warning and it is treated as error on build environment of perf.
GCC says "cast from function call of type âlong long unsigned intâ to 
non-matching type âvoid *â".
# Why is tmp to acquire_event.addr allowed? It's mysterious...

So I declared "u64 tmp" as temporary place for casting.
But next, this tmp causes compile error on x86_32.
Because it is u64. tmp should be u32 on x86_32.

I have to switch type of tmp u64 or u32 based on environment.
Don't you know some good preprocessor flag or some other avoiding methods?
I seeked but not found...

Thanks,
	Hitoshi
--
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/