Question : Windows 7 and its dispatcher spin lock, and what about Linux kernel

Was watching Mark Russinovich talking about the redesigned dispatcher lock in the new Windows 7 kernel.  The lock was single and global in previous Windows versions, which will become a bottleneck in a massively multicore system.  The newly designed the lock has a "tiered" approach, so the fine grained locking mechanism wouldn't create too much blocking.  That'll enable easy scaling to 256 cores.

That's certainly good.  Anyone has any insight on similar issues for Linux kernel?  I'm not talking about highly optimized ones running on things like Cray.  How about the run of the mill kernel that's in our desktop distributions?  Does it have any major global locks that may impede like the old Windows dispatcher lock?  Not really a pro on Linux kernel so haven't found any good literature on that.  Hopefully experts here may have a pointer or two.  Good links would be much appreciated.

Answer : Windows 7 and its dispatcher spin lock, and what about Linux kernel

Linux can handle 32 CPUs in a 32bit install and 64 in a 64bit install (which is the same for Vista and XP).  If you have a Linux cluster system then it can handel 1024.
https://answers.launchpad.net/ubuntu/+question/9820

In kernel 2.6 Linux uses the "Process Scheduler" to manage the different cores and hyper threading, similar but different, then the dispatcher lock.
Info on how linux kernel 2.6 handles multiple cores. See page 3
http://software.intel.com/sites/oss/pdf/mclinux.pdf

Have you seen what 256 cores look like in Win7?
http://software.intel.com/en-us/blogs/2009/01/05/what-does-256-cores-look-like/