Re: [Qemu-devel] [PATCH 03/12] rcu: add rcu library

[Stefan Hajnoczi]

On Wed, May 15, 2013 at 05:48:48PM +0200, Paolo Bonzini wrote:
> +RCU PATTERNS
> +============
> +
> +Many patterns using read-writer locks translate directly to RCU, with
> +the advantages of higher scalability and deadlock immunity.
> +
> +In general, RCU can be used whenever it is possible to create a new
> +"version" of a data structure every time the updater runs.  This may
> +sound like a very strict restriction, however:
> +
> +- the updater does not mean "everything that writes to a data structure",
> +  but rather "everything that involves a reclamation step".  See the
> +  array example below
> +
> +- in some cases, creating a new version of a data structure may actually
> +  be very cheap.  For example, modifying the "next" pointer of a singly
> +  linked list is effectively creating a new version of the list.
> +
> +
> +them however are worth noting.

?