[IA64] Add __read_mostly support for IA64

dc86e88c · Christoph Lameter <[email protected]> · 2005-12-12 09:34:32 -08:00

sparc64, i386 and x86_64 have support for a special data section dedicated
to rarely updated data that is frequently read. The section was created to
avoid false sharing of those rarely read data with frequently written kernel
data.

This patch creates such a data section for ia64 and will group rarely written
data into this section.

Signed-off-by: Christoph Lameter <[email protected]>
Signed-off-by: Tony Luck <[email protected]>

Commit: dc86e88c2bb8a7603ee175fbb6a9e92cf3293dd8
Parents: d5bf3165

Changes

2 files changed · +4 −1

File	Status	Add	Del	Content
arch/ia64/kernel/vmlinux.lds.S	modified	+3	−0	View file
include/linux/cache.h	modified	+1	−1	View file

arch/ia64/kernel/vmlinux.lds.S

View file

diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 30d8564..73af626 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -177,6 +177,9 @@ SECTIONS
 	}
   . = ALIGN(PAGE_SIZE);		/* make sure the gate page doesn't expose kernel data */
 
+  .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET)
+        { *(.data.read_mostly) }
+
   .data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET)
         { *(.data.cacheline_aligned) }
 

include/linux/cache.h

View file

diff --git a/include/linux/cache.h b/include/linux/cache.h
index f6b5a46..0b7ecf3 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -13,7 +13,7 @@
 #define SMP_CACHE_BYTES L1_CACHE_BYTES
 #endif
 
-#if defined(CONFIG_X86) || defined(CONFIG_SPARC64)
+#if defined(CONFIG_X86) || defined(CONFIG_SPARC64) || defined(CONFIG_IA64)
 #define __read_mostly __attribute__((__section__(".data.read_mostly")))
 #else
 #define __read_mostly