percpu: align percpu readmostly subsection to cacheline

Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.

This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.

This is based on Shaohua's x86 only patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/cris/kernel/vmlinux.lds.S b/arch/cris/kernel/vmlinux.lds.S
index 442218980db0..c62e1346f47c 100644
--- a/arch/cris/kernel/vmlinux.lds.S
+++ b/arch/cris/kernel/vmlinux.lds.S
@@ -107,7 +107,7 @@ SECTIONS
 #endif
         __vmlinux_end = .;              /* Last address of the physical file. */
 #ifdef CONFIG_ETRAX_ARCH_V32
-        PERCPU(PAGE_SIZE)
+        PERCPU(32, PAGE_SIZE)
 
         .init.ramfs : {
                 INIT_RAM_FS