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Definition of RCU needed

Definition of RCU needed

Posted Oct 12, 2006 23:48 UTC (Thu) by giraffedata (subscriber, #1954)
In reply to: Sleepable RCU by HappyCamp
Parent article: Sleepable RCU

Does "Read Copy Update" mean something to you? I don't think it says any more than "RCU." In fact, since I know what RCU is, I would have needed the text to explain that "Read Copy Update" means RCU. A couple of sentences definining RCU are definitely called for, but the etymology of the acronym alone would be pretty useless.

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Definition of RCU needed

Posted Oct 14, 2006 14:45 UTC (Sat) by kevinbsmith (guest, #4778) [Link]

"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 (subscriber, #9624) [Link]

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:

Definition of RCU

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

> (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 (subscriber, #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.

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