Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Mon, 24 Apr 2006 17:06:03 +0200 | From | Martin Schwidefsky <> | Subject | [patch 12/13] s390: add read_mostly optimization. |
| |
From: Christian Borntraeger <cborntra@de.ibm.com>
[patch 12/13] s390: add read_mostly optimization.
Add a read_mostly section and define __read_mostly to prevent cache line pollution due to writes for mostly read variables. In addition fix the incorrect alignment of the cache_line_aligned data section. s390 has a cacheline size of 256 bytes.
Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> ---
arch/s390/kernel/vmlinux.lds.S | 4 +++- include/asm-s390/cache.h | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-)
diff -urpN linux-2.6/arch/s390/kernel/vmlinux.lds.S linux-2.6-patched/arch/s390/kernel/vmlinux.lds.S --- linux-2.6/arch/s390/kernel/vmlinux.lds.S 2006-03-20 06:53:29.000000000 +0100 +++ linux-2.6-patched/arch/s390/kernel/vmlinux.lds.S 2006-04-24 16:47:29.000000000 +0200 @@ -58,9 +58,11 @@ SECTIONS . = ALIGN(4096); .data.page_aligned : { *(.data.idt) } - . = ALIGN(32); + . = ALIGN(256); .data.cacheline_aligned : { *(.data.cacheline_aligned) } + . = ALIGN(256); + .data.read_mostly : { *(.data.read_mostly) } _edata = .; /* End of data section */ . = ALIGN(8192); /* init_task */ diff -urpN linux-2.6/include/asm-s390/cache.h linux-2.6-patched/include/asm-s390/cache.h --- linux-2.6/include/asm-s390/cache.h 2006-03-20 06:53:29.000000000 +0100 +++ linux-2.6-patched/include/asm-s390/cache.h 2006-04-24 16:47:29.000000000 +0200 @@ -16,4 +16,6 @@ #define ARCH_KMALLOC_MINALIGN 8 +#define __read_mostly __attribute__((__section__(".data.read_mostly"))) + #endif - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| ![\](/images/icornerr.gif) |