PERFORCE change 87656 for review

[John Baldwin]

http://perforce.freebsd.org/chv.cgi?CH=87656

Change 87656 by jhb at jhb_slimer on 2005/12/02 21:21:58

	Suggestion from Kris.

Affected files ...

.. //depot/projects/smpng/sys/notes#67 edit

Differences ...

==== //depot/projects/smpng/sys/notes#67 (text+ko) ====

@@ -75,6 +75,10 @@
     - arm, powerpc?
   - fork counts?
 - Add a cache-line padded mtx_aligned union and use it for the mutex pools.
+- Add a per-thread counter of the number of sleep mutexes held (including
+  recursion) and panic if we try to sleep with any held to provide a cheaper
+  version of the current WITNESS check that doesn't bog the system down quite
+  as bad.
 
 Active child branches:
 - jhb_intr - fast ithreads and MSI? (perhaps do MSI in jhb_acpipci)