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@xxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/cache.h | 2 ++
arch/arm/kernel/vmlinux.lds.S | 1 +
2 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
index 9d61220..75fe66b 100644
--- 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
index cead889..1581f6d 100644
--- 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)
--
1.6.2.5
--
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