Definition of RCU needed

Posted Oct 14, 2006 14:45 UTC (Sat) by kevinbsmith (guest, #4778)
In reply to: Definition of RCU needed by giraffedata
Parent article: Sleepable RCU

"Does 'Read Copy Update' mean something to you?"

Yes. I have heard the term before, but didn't immediately think of it when I saw RCU. I had the same reaction as the parent poster ("What the #$#$ is RCU?". If the article had started "Classic RCU (Read-Copy-Update) requires that..." I would not have had that reaction.

LWN is usually excellent about this. It's one of the few places where release announcements for software packages regularly include a brief summary of what the FooBar package actually does. That's one reason this RCU case really jumped out.

Definition of RCU

Posted Oct 14, 2006 22:03 UTC (Sat) by PaulMcKenney (✭ supporter ✭, #9624) [Link] (2 responses)

My apologies for leaving out this definition!!!

RCU does indeed stand for read-copy update. The name comes from the fact that readers continue to freely access the data structures even while another thread is making and substituting a copy in order to update. More information may be found at:

http://lwn.net/Articles/37889/ (though from 2003, guess I need to get Jon an update...) -- and Jon has written quite a bit about RCU, as you can see from Googling "read copy update site:lwn.net".
http://en.wikipedia.org/wiki/RCU (I update this, so please let me know if you find bugs.)
http://www.rdrop.com/users/paulmck/RCU/

Definition of RCU

Posted Oct 16, 2006 4:19 UTC (Mon) by xoddam (guest, #2322) [Link] (1 responses)

> http://en.wikipedia.org/wiki/RCU
> (I update this, so please let me know if you find bugs.)

Presumably you update a copy whilst we read the previous version :-)

Updating wikipedia

Posted Oct 16, 2006 13:12 UTC (Mon) by PaulMcKenney (✭ supporter ✭, #9624) [Link]

;-) ;-) ;-)

But as near as I can tell, that is exactly what happens. Although I have no idea what algorithm wikis use to accomplish this.