What's the best linux kernel locking mechanism for a specific scenario

I need to solve a locking problem for this scenario:

1. A multi CPU system.
2. All of the CPU's use a common (software) resource.
3. Read only access to the resource is very common. (Processing of incoming network packets)
4. Write access is a lot less frequent. (Pretty much configuration changes only).

Currently I use the read_lock_bh, write_lock_bh (spinlocks) mechanism. The problem is that the more CPU's, the more I get soft lockups in a writer context.

I read the concurrency chapter in this book, But couldn't quite understand whether the reader or the writer will get priority when using spin locks.

So the questions are:

1. Does the Linux spinlock mechanism give priority the reader/writer/none of them?
2. Is there a better mechanism I can use in order to avoid those soft lockups in my scenario, or maybe a way for me to give priority to the writer whenever it tries to obtain the lock, while using my current solution?

Thanks, Nir