[intel-platform-dev] Code review for several MONITOR/MWAIT idle loop CRs

[Bill Holler]

http://cr.opensolaris.org/~bholler/mwait_fixes

Here is a webrev code review for the following idle loop MONITOR/MWAIT
CRs (Change Requests):

6577948 <http://monaco.sfbay.sun.com/detail.jsp?cr=6577948> 
mach_alloc_mwait leaks memory when a CPU fails to start
6588054 <http://monaco.sfbay.sun.com/detail.jsp?cr=6588054> panic() in 
mach_alloc_mwait() should be changed to degraded operation...
6596141 <http://monaco.sfbay.sun.com/detail.jsp?cr=6596141> Solaris 
should not use an unmodified MWAIT idle loop on AMD 10h due to increased 
power consumption


While these are relatively low priority, I want to get these in soon for
maximum S10U5 soak time.

Testing completed:
1) The x86 build of this kernel has passed ON PIT DIY.  The SPARC build
     is currently in ON PIT DIY and looks ok.  (There are no common changes
     that should effect SPARC.)
2) libmicro did not regress.
    PERF PIT is not planned as these are enable/disable changes which should
    not change performance in either state.
3) The memory leak is fiked in unit testing with all non-boot cpus forced to
    fail to online using cpufailset debug hook.
4) My desktop has been running this for 2 weeks without incident.

Ongoing testing:
1) Barcelona testing is ongoing.
2) 6588054 error injection testing is ongoing.

Thank you,
Bill Holler