svn commit: r333486 - head/sys/conf

[Mateusz Guzik]

Author: mjg
Date: Fri May 11 08:56:39 2018
New Revision: 333486
URL: https://svnweb.freebsd.org/changeset/base/333486

Log:
  amd64: align the .data.exclusive_cache_line section to 128
  
  This aligns the section itself compared to other sections, does not change
  internal alignment of fields stored inside. This may or may not come later.
  
  The motivation is partially combating adverse effects of the adjacent cache
  line prefetcher. Without the annotation part of read_mostly section was on
  the line of fire.

Modified:
  head/sys/conf/ldscript.amd64

Modified: head/sys/conf/ldscript.amd64
==============================================================================
--- head/sys/conf/ldscript.amd64	Fri May 11 08:16:56 2018	(r333485)
+++ head/sys/conf/ldscript.amd64	Fri May 11 08:56:39 2018	(r333486)
@@ -155,12 +155,12 @@ SECTIONS
   {
     *(.data.read_mostly)
   }
-  . = ALIGN(64);
+  . = ALIGN(128);
   .data.exclusive_cache_line :
   {
     *(.data.exclusive_cache_line)
   }
-  . = ALIGN(64);
+  . = ALIGN(128);
   .data           :
   {
     *(.data .data.* .gnu.linkonce.d.*)