svn commit: r225888 - head/sys/sparc64/sparc64

[Marius Strobl]

Author: marius
Date: Fri Sep 30 20:23:18 2011
New Revision: 225888
URL: http://svn.freebsd.org/changeset/base/225888

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

Modified:
  head/sys/sparc64/sparc64/machdep.c

Modified: head/sys/sparc64/sparc64/machdep.c
==============================================================================
--- head/sys/sparc64/sparc64/machdep.c	Fri Sep 30 20:13:51 2011	(r225887)
+++ head/sys/sparc64/sparc64/machdep.c	Fri Sep 30 20:23:18 2011	(r225888)
@@ -1015,6 +1015,10 @@ exec_setregs(struct thread *td, struct i
 	tf->tf_out[6] = sp - SPOFF - sizeof(struct frame);
 	tf->tf_tnpc = imgp->entry_addr + 4;
 	tf->tf_tpc = imgp->entry_addr;
+	/*
+	 * 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];