[Fwd: Re: Lockless algorithms [was Re: splxxx replacements?]]

[Julian Elischer]

Ivan Voras wrote:

> 
> There are patent issues and the GPL license, but this is just too
> powerful an
> algorithm to ignore. In many way, this brings out the ultimate in what
> shared
> memory system can do.
> 

I don;t think that patent issues can be to much of an issue as RCU (as 
it is in my understanding) has been used in the kernel since the very 
earliest of days, even before there was SMP.


Take the example of a file reference to an inode..
you want file X.
you open it
someone deletes it and creates a new one.
you still have your copy to work on until you are finished with it..
when you finish, the reference count on the inode goes to 0 and it is 
freed.
The other process can update the new version of the file without 
worrying about colliding with your copy.

 From my understanding this is RCU. (unless I'm thinking of a different 
RCU :-)