ARM: implement support for read-mostly sections

As our SMP implementation uses MESI protocols. Grouping together data which is mostly only read together means that we avoid unnecessary cache line bouncing when this code shares a cache line with other data. In other words, cache lines associated with read-mostly data are expected to spend most of their time in shared state. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
git-mirror · Dec 5, 2010 · daf8741 · daf8741
1 parent 0b05da7
commit daf8741
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diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
@@ -23,4 +23,6 @@
 #define ARCH_SLAB_MINALIGN 8
 #endif
 
+#define __read_mostly __attribute__((__section__(".data..read_mostly")))
+
 #endif
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
@@ -167,6 +167,7 @@ SECTIONS
 
 		NOSAVE_DATA
 		CACHELINE_ALIGNED_DATA(32)
+		READ_MOSTLY_DATA(32)
 
 		/*
 		 * The exception fixup table (might need resorting at runtime)
-Original file line number
+Diff line change
@@ Expand Up / @@ -23,4 +23,6 @@ @@
     #define ARCH_SLAB_MINALIGN 8
     #endif
+    #define __read_mostly __attribute__((__section__(".data..read_mostly")))
     #endif