What kind of Garbage Collection does Go use?

Go is a garbage collected language:

http://golang.org/doc/go_faq.html#garbage_collection

Here it says that it's a mark-and-sweep garbage collector, but it doesn't delve into details, and a replacement is in the works... yet, this paragraph seems not to have been updated much since Go was released.

It's still mark-and-sweep? Is it conservative or precise? Is it generational?

Plans for Go 1.4+ garbage collector:

• hybrid stop-the-world/concurrent collector

• stop-the-world part limited by a 10ms deadline

• CPU cores dedicated to running the concurrent collector

• tri-color mark-and-sweep algorithm

• non-generational

• non-compacting

• fully precise

• incurs a small cost if the program is moving pointers around

• lower latency, but most likely also lower throughput, than Go 1.3 GC

Go 1.3 garbage collector updates on top of Go 1.1:

• concurrent sweep (results in smaller pause times)

• fully precise

Go 1.1 garbage collector:

• mark-and-sweep (parallel implementation)

• non-generational

• non-compacting

• mostly precise (except stack frames)

• stop-the-world

• bitmap-based representation

• zero-cost when the program is not allocating memory (that is: shuffling pointers around is as fast as in C, although in practice this runs somewhat slower than C because the Go compiler is not as advanced as C compilers such as GCC)

• supports finalizers on objects

• there is no support for weak references

Go 1.0 garbage collector:

• same as Go 1.1, but instead of being mostly precise the garbage collector is conservative. The conservative GC is able to ignore objects such as []byte.

Replacing the GC with a different one is controversial, for example:

• except for very large heaps, it is unclear whether a generational GC would be faster overall

• package "unsafe" makes it hard to implement fully precise GC and compacting GC

Stack Overflow Q#7823725, score: 121