From b077ffb3b767c3efb44d00b998385a9cb127255c Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Fri, 16 Feb 2007 01:48:11 -0800 Subject: rdmsr_on_cpu, wrmsr_on_cpu There was OpenVZ specific bug rendering some cpufreq drivers unusable on SMP. In short, when cpufreq code thinks it confined itself to needed cpu by means of set_cpus_allowed() to execute rdmsr, some "virtual cpu" feature can migrate process to anywhere. This triggers bugons and does wrong things in general. This got fixed by introducing rdmsr_on_cpu and wrmsr_on_cpu executing rdmsr and wrmsr on given physical cpu by means of smp_call_function_single(). Dave Jones mentioned cpufreq might be not only user of rdmsr_on_cpu() and wrmsr_on_cpu(), so I'm putting them into arch/{i386,x86_64}/lib/ . Signed-off-by: Alexey Dobriyan Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- arch/i386/lib/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/i386/lib/Makefile') diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile index d86a548b8d5..0d41223472c 100644 --- a/arch/i386/lib/Makefile +++ b/arch/i386/lib/Makefile @@ -7,3 +7,5 @@ lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \ bitops.o semaphore.o lib-$(CONFIG_X86_USE_3DNOW) += mmx.o + +obj-y = msr-on-cpu.o -- cgit v1.2.3-18-g5258 From b44755cfaa72e7ed3d831a946bb4e7dfe7548966 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Tue, 20 Feb 2007 01:07:13 +0100 Subject: {rd,wr}msr_on_cpu SMP=n optimization Let's save a few bytes in the CONFIG_SMP=n case. Signed-off-by: Adrian Bunk Signed-off-by: Dave Jones --- arch/i386/lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/i386/lib/Makefile') diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile index 0d41223472c..22d8ac5815f 100644 --- a/arch/i386/lib/Makefile +++ b/arch/i386/lib/Makefile @@ -8,4 +8,4 @@ lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \ lib-$(CONFIG_X86_USE_3DNOW) += mmx.o -obj-y = msr-on-cpu.o +obj-$(CONFIG_SMP) += msr-on-cpu.o -- cgit v1.2.3-18-g5258