svn commit: r230672 - stable/8/sys/sparc64/sparc64

[Marius Strobl]

Author: marius
Date: Sat Jan 28 23:18:02 2012
New Revision: 230672
URL: http://svn.freebsd.org/changeset/base/230672

Log:
  MFC: r225888
  
  Add a comment about why contrary to what once would think running all of
  userland with total store order actually is appropriate.

Modified:
  stable/8/sys/sparc64/sparc64/machdep.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)

Modified: stable/8/sys/sparc64/sparc64/machdep.c
==============================================================================
--- stable/8/sys/sparc64/sparc64/machdep.c	Sat Jan 28 23:17:58 2012	(r230671)
+++ stable/8/sys/sparc64/sparc64/machdep.c	Sat Jan 28 23:18:02 2012	(r230672)
@@ -1014,6 +1014,10 @@ exec_setregs(struct thread *td, u_long e
 	tf->tf_out[6] = sp - SPOFF - sizeof(struct frame);
 	tf->tf_tnpc = entry + 4;
 	tf->tf_tpc = entry;
+	/*
+	 * While we could adhere to the memory model indicated in the ELF
+	 * header, it turns out that just always using TSO performs best.
+	 */
 	tf->tf_tstate = TSTATE_IE | TSTATE_PEF | TSTATE_MM_TSO;
 
 	td->td_retval[0] = tf->tf_out[0];