Re: [PATCH/RFC 1/2] jump label: make enable/disable o(1)

[Peter Zijlstra]

On Thu, 2010-12-16 at 14:23 -0500, Jason Baron wrote:
> 
> For the jump label disabled case, perf is using atomic_inc/dec and atomic_read
> to check if enabled. While other consumers (tracepoints) are just using an
> 'int'. I didn't want hurt the jump label disabled case for tracepoints.
> If we can agree to use atomic ops for tracepoints, or drop atomics from
> perf, that would simplify things. 

I had a quick look at the tracepoint stuff but got lost, but surely it
has a reference count somewhere as well, it needs to know when the last
probe goes away.. or does it check if the list is empty?

Anyway, tracepoint enable/disable isn't a real fast-path, surely it
could suffer an atomic op?
--
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/