svn commit: r262753 - stable/10/sys/amd64/amd64

[Ed Maste]

Author: emaste
Date: Tue Mar  4 21:51:09 2014
New Revision: 262753
URL: http://svnweb.freebsd.org/changeset/base/262753

Log:
  Disable amd64 TLB Context ID (pcid) by default for now
  
  There are a number of reports of userspace application crashes that
  are "solved" by setting vm.pmap.pcid_enabled=0, including Java and the
  x11/mate-terminal port (PR ports/184362).
  
  For now apply a band-aid of disabling pcid by default in stable/10.
  
  Sponsored by:	The FreeBSD Foundation

Modified:
  stable/10/sys/amd64/amd64/pmap.c

Modified: stable/10/sys/amd64/amd64/pmap.c
==============================================================================
--- stable/10/sys/amd64/amd64/pmap.c	Tue Mar  4 21:35:57 2014	(r262752)
+++ stable/10/sys/amd64/amd64/pmap.c	Tue Mar  4 21:51:09 2014	(r262753)
@@ -367,7 +367,7 @@ static int pmap_flags = PMAP_PDE_SUPERPA
 
 static struct unrhdr pcid_unr;
 static struct mtx pcid_mtx;
-int pmap_pcid_enabled = 1;
+int pmap_pcid_enabled = 0;
 SYSCTL_INT(_vm_pmap, OID_AUTO, pcid_enabled, CTLFLAG_RDTUN, &pmap_pcid_enabled,
     0, "Is TLB Context ID enabled ?");
 int invpcid_works = 0;