Strawman proposal: making libthr default thread implementation?

[Kip Macy]

Hi, as some of you may know, I've been working on a port to the sun4v.
This has motivated me to take a closer look at some of our locking.
One glaring item is the existence of sched_lock that serializes
context switches and thread state changes across all 32 logical cpus.
I'm interested in adding somewhat finer-grained locking, but this is
made more complicated by the kernel-side implementation of KSE.

I find it worthy of note, that Sun dropped support for scheduler
activations in Solaris because their engineers recognized that most
significant applications are written with the assumption of
linux-style system scope threads. Can someone please point me at
real-world applications that are used to compare FreeBSD and Linux
that rely on PROCESS_SCOPE and or general scheduler activation
semantics?
  -Kip