[-mm patch] {rd,wr}msr_on_cpu SMP=n optimization

From: Adrian Bunk
Date: Mon Feb 19 2007 - 19:21:30 EST


On Thu, Feb 15, 2007 at 05:14:08AM -0800, Andrew Morton wrote:
>...
> Changes since 2.6.20-rc6-mm3:
>...
> +rdmsr_on_cpu-wrmsr_on_cpu.patch
>...
> x86 updates
>...

Let's save a few bytes in the CONFIG_SMP=n case.

Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>

---

BTW: currently -ENOUSERS

arch/i386/lib/Makefile | 2 +-
arch/i386/lib/msr-on-cpu.c | 12 ------------
arch/x86_64/lib/Makefile | 3 ++-
include/asm-i386/msr.h | 11 +++++++++++
include/asm-x86_64/msr.h | 11 +++++++++++
5 files changed, 25 insertions(+), 14 deletions(-)

--- linux-2.6.20-mm1/arch/i386/lib/Makefile.old 2007-02-16 14:13:20.000000000 +0100
+++ linux-2.6.20-mm1/arch/i386/lib/Makefile 2007-02-16 14:14:22.000000000 +0100
@@ -8,4 +8,4 @@

lib-$(CONFIG_X86_USE_3DNOW) += mmx.o

-obj-y = msr-on-cpu.o
+obj-$(CONFIG_SMP) += msr-on-cpu.o
--- linux-2.6.20-mm1/arch/x86_64/lib/Makefile.old 2007-02-16 14:13:52.000000000 +0100
+++ linux-2.6.20-mm1/arch/x86_64/lib/Makefile 2007-02-16 14:14:14.000000000 +0100
@@ -4,7 +4,8 @@

CFLAGS_csum-partial.o := -funroll-loops

-obj-y := io.o iomap_copy.o msr-on-cpu.o
+obj-y := io.o iomap_copy.o
+obj-$(CONFIG_SMP) += msr-on-cpu.o

lib-y := csum-partial.o csum-copy.o csum-wrappers.o delay.o \
usercopy.o getuser.o putuser.o \
--- linux-2.6.20-mm1/include/asm-i386/msr.h.old 2007-02-16 14:14:43.000000000 +0100
+++ linux-2.6.20-mm1/include/asm-i386/msr.h 2007-02-16 14:16:00.000000000 +0100
@@ -83,8 +83,19 @@
: "c" (counter))
#endif /* !CONFIG_PARAVIRT */

+#ifdef CONFIG_SMP
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+#else /* CONFIG_SMP */
+static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+ rdmsr(msr_no, *l, *h);
+}
+static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+ wrmsr(msr_no, l, h);
+}
+#endif /* CONFIG_SMP */

/* symbolic names for some interesting MSRs */
/* Intel defined MSRs. */
--- linux-2.6.20-mm1/include/asm-x86_64/msr.h.old 2007-02-16 14:16:12.000000000 +0100
+++ linux-2.6.20-mm1/include/asm-x86_64/msr.h 2007-02-16 14:16:50.000000000 +0100
@@ -160,8 +160,19 @@
#define MSR_IA32_UCODE_WRITE 0x79
#define MSR_IA32_UCODE_REV 0x8b

+#ifdef CONFIG_SMP
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+#else /* CONFIG_SMP */
+static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+ rdmsr(msr_no, *l, *h);
+}
+static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+ wrmsr(msr_no, l, h);
+}
+#endif /* CONFIG_SMP */

#endif

--- linux-2.6.20-mm1/arch/i386/lib/msr-on-cpu.c.old 2007-02-16 14:17:06.000000000 +0100
+++ linux-2.6.20-mm1/arch/i386/lib/msr-on-cpu.c 2007-02-16 14:17:49.000000000 +0100
@@ -3,7 +3,6 @@
#include <linux/smp.h>
#include <asm/msr.h>

-#ifdef CONFIG_SMP
struct msr_info {
u32 msr_no;
u32 l, h;
@@ -54,17 +53,6 @@
}
preempt_enable();
}
-#else
-void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
-{
- rdmsr(msr_no, *l, *h);
-}
-
-void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
-{
- wrmsr(msr_no, l, h);
-}
-#endif

EXPORT_SYMBOL(rdmsr_on_cpu);
EXPORT_SYMBOL(wrmsr_on_cpu);
-
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