Is there any change in .Net 4.0 garbage collector execution?
There's also an ephemeron implemenation using a new class called System.Runtime.CompilerServices.ConditionalWeakTable which is detailed here.
This is useful for collecting dynamic languages which allow setting arbitary "properties" on arbitrary instances.
Here's a blog posting:
http://geekswithblogs.net/sdorman/archive/2008/11/07/clr-4.0-garbage-collection-changes.aspx
and
http://www.infoq.com/news/2009/06/Background-Collector
Yes, lots.
My latest book Visual F# 2010 for Technical Computing includes a lot of performance-related information about .NET 4 as well as F# itself and the performance measurements and advice are quite different with .NET 4 and the new background garbage collector. In many cases we're seeing substantial performance improvements but there are some slowdowns as well.
Also, check out the blog of the developer who works on the GC, where there is an article about the new GC, plus a link to a Channel 9 interview regarding the .NET 4.0 GC.
There is also AppDomainResourceManager feature, which allows you to track resource usage ( Memory and CPU ) per appdomain. the GC part of this feature is the ability to get per appdomain memory tracking.