Re: JavaMemoryModel: Another software-only solution

From: Ole Agesen - SunLabs (agesen@galileo.East.Sun.COM)
Date: Thu Jul 01 1999 - 18:24:43 EDT


> If we assume that this reordering might happen due to stale cache
> lines, rather than value prediction, here is a solution. In the
> nursery, always allocate objects starting at the beginning of a new
> cache line.
> ...
> Now, of course this wastes some space, but only in the nursery. When
> the garbage collector moves objects out of the nursery, it can store
> them compactly.

I'd like to throw in a caution here. The nursery or youngest
generation (or whatever you call it) is the high pressure end
of the memory system. Any overhead introduced there, will make
itself visible! In the above case, the overhead is on every allocated
object, not just on every object that survives a collection.

Ole

-------------------------------
This is the JavaMemoryModel mailing list, managed by Majordomo 1.94.4.

To send a message to the list, email JavaMemoryModel@cs.umd.edu
To send a request to the list, email majordomo@cs.umd.edu and put
your request in the body of the message (use the request "help" for help).
For more information, visit http://www.cs.umd.edu/~pugh/java/memoryModel



This archive was generated by hypermail 2b29 : Thu Oct 13 2005 - 07:00:14 EDT