[PATCH] powerpc: book3e_64: fix the align size for paca_struct

Kevin Hao haokexin at gmail.com
Sat Mar 7 22:14:53 AEDT 2015


All the cache line size of the current book3e 64bit SoCs are 64 bytes.
So we should use this size to align the member of paca_struct.
With this change we save 192 bytes. Also change it to __aligned(size)
since it is preferred over __attribute__((aligned(size))).

Before:
	/* size: 1920, cachelines: 30, members: 46 */
	/* sum members: 1667, holes: 6, sum holes: 141 */
	/* padding: 112 */

After:
	/* size: 1728, cachelines: 27, members: 46 */
	/* sum members: 1667, holes: 4, sum holes: 13 */
	/* padding: 48 */

Signed-off-by: Kevin Hao <haokexin at gmail.com>
---
 arch/powerpc/include/asm/paca.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index e5f22c6c4bf9..70bd4381f8e6 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -106,9 +106,9 @@ struct paca_struct {
 #endif /* CONFIG_PPC_STD_MMU_64 */
 
 #ifdef CONFIG_PPC_BOOK3E
-	u64 exgen[8] __attribute__((aligned(0x80)));
+	u64 exgen[8] __aligned(0x40);
 	/* Keep pgd in the same cacheline as the start of extlb */
-	pgd_t *pgd __attribute__((aligned(0x80))); /* Current PGD */
+	pgd_t *pgd __aligned(0x40); /* Current PGD */
 	pgd_t *kernel_pgd;		/* Kernel PGD */
 
 	/* Shared by all threads of a core -- points to tcd of first thread */
-- 
2.1.0



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