AMD FX-8150 Bulldozer On Ubuntu Linux
In terms of any "sweet spot" or an ideal level of Bulldozer Linux support, it is not there quite yet. Similar to how Microsoft Windows 8 will offer up measurable performance improvements for Bulldozer over Windows 7, the Linux support can also be optimized for this distinct AMD architecture.
The GCC and Open64 compilers have received optimizations for Bulldozer (available from the "bdver1" architecture flag) and the first bits of that work were committed in 2010. GCC 4.5/4.6 already have basic Bulldozer support in place, along with Open64, and it will likely receive more improvements going forward (e.g. it doesn't appear that the GCC patch for implementing the dispatch scheduler has yet to be merged to mainline). The article looking specifically at the compiler performance will go into more detail on what has been optimized within the leading open-source / Linux compilers for Bulldozer.
Outside of the compilers, there are still yet-to-be-merged kernel-level optimizations. Over the summer, there was the "Correct F15h IC aliasing issue" patch by AMD's Borislav Petkov that was meant to improve the Bulldozer performance in some workloads. Linus Torvalds criticized this work and it has yet to be merged mainline, but hopefully it will be a candidate for the Linux 3.2 kernel. I have also reached out to Borislav to find out about any other upcoming Bulldozer Linux patches, but am still waiting on hearing back from the AMD developer in Munich.
With the Linux 3.0/3.1 kernel, the "k10temp" driver supports reading the core temperature of the FX-8150. There's also a new driver that was merged this summer and its the "fam15h_power" driver, which is for taking advantage of new registers found on the Bulldozer CPUs that allow reading the estimated power consumption of the CPU itself without any external equipment. Unfortunately, as will be talked about in the overclocking article, this is not terribly accurate and when pushing the CPU hard it can provide wildly wrong results (e.g. 14W power consumption when overclocking her to 4.7GHz).
The Phoronix Test Suite already supports monitoring these drivers via their sysfs interfaces for automatic polling during the benchmarking process. There are various Bulldozer system detection improvements that have landed within Phoronix Test Suite 3.6-Arendal. Another note about the management Linux support for Bulldozer is that the Asetek/AMD FX water cooling system has a USB interface for controlling and monitoring the fan speeds of this CPU cooler. Unfortunately, there is no Linux software for this USB controller nor have I seen AMD/Asetek provide any technical documentation to allow a driver to be created.
Simply put, the Linux support is there for the AMD Bulldozer processors if you are using a recent Linux distribution, as long as your motherboard is compatible. Running the latest release of your Linux distribution is certainly recommended and expect for performance optimizations and other support improvements to still come down the pipe.