Re: [patch] x86_64: fix sched_clock()

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Fri, 2007-05-25 at 09:54 +0200, Ingo Molnar wrote:
> Subject: [patch] x86_64: fix sched_clock()
> From: Ingo Molnar <mingo@elte.hu>
> 
> sched_clock() is totally broken on x86_64, because it is not defined by 
> the architecture at all! It fell the victim to the opaqueness of 
> __attribute__((weak)) and to non-testing.
> 
> the i386 version was supposed to be used. This patch fixes that. Booted 
> and tested on x86_64 and i386.
> 
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

This does indeed solve my issue.

> ---
>  arch/x86_64/kernel/Makefile |    3 ++-
>  include/asm-x86_64/tsc.h    |    5 +++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> Index: linux-cfs-2.6.22-rc2-mm1.q/arch/x86_64/kernel/Makefile
> ===================================================================
> --- linux-cfs-2.6.22-rc2-mm1.q.orig/arch/x86_64/kernel/Makefile
> +++ linux-cfs-2.6.22-rc2-mm1.q/arch/x86_64/kernel/Makefile
> @@ -9,7 +9,7 @@ obj-y	:= process.o signal.o entry.o trap
>  		x8664_ksyms.o i387.o syscall.o vsyscall.o \
>  		setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \
>  		pci-dma.o pci-nommu.o alternative.o hpet.o tsc.o bugs.o \
> -		perfctr-watchdog.o
> +		perfctr-watchdog.o sched-clock.o
>  
>  obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
>  obj-$(CONFIG_X86_MCE)		+= mce.o therm_throt.o
> @@ -49,6 +49,7 @@ obj-y				+= pcspeaker.o
>  
>  CFLAGS_vsyscall.o		:= $(PROFILING) -g0
>  
> +sched-clock-y			+= ../../i386/kernel/sched-clock.o
>  therm_throt-y                   += ../../i386/kernel/cpu/mcheck/therm_throt.o
>  bootflag-y			+= ../../i386/kernel/bootflag.o
>  legacy_serial-y			+= ../../i386/kernel/legacy_serial.o
> Index: linux-cfs-2.6.22-rc2-mm1.q/include/asm-x86_64/tsc.h
> ===================================================================
> --- linux-cfs-2.6.22-rc2-mm1.q.orig/include/asm-x86_64/tsc.h
> +++ linux-cfs-2.6.22-rc2-mm1.q/include/asm-x86_64/tsc.h
> @@ -1 +1,6 @@
>  #include <asm-i386/tsc.h>
> +
> +/*
> + * To be able to share sched-clock.c between i386 and x86_64:
> + */
> +#define tsc_disable 0
>