Re: [PATCH 1/2] xenoprof: fix up ability to disable it

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 08/02/16 16:04, Doug Goldstein wrote:
> diff --git a/xen/arch/x86/cpu/vpmu_amd.c b/xen/arch/x86/cpu/vpmu_amd.c
> index 990e6f3..c7b5bd5 100644
> --- a/xen/arch/x86/cpu/vpmu_amd.c
> +++ b/xen/arch/x86/cpu/vpmu_amd.c
> @@ -22,6 +22,7 @@
>   */
>  
>  #include <xen/config.h>
> +#include <xen/kconfig.h>
>  #include <xen/xenoprof.h>
>  #include <xen/hvm/save.h>
>  #include <xen/sched.h>
> @@ -378,7 +379,8 @@ static int amd_vpmu_do_wrmsr(unsigned int msr, uint64_t msr_content,
>      if ( (type == MSR_TYPE_CTRL) &&
>          is_pmu_enabled(msr_content) && !vpmu_is_set(vpmu, VPMU_RUNNING) )
>      {
> -        if ( !acquire_pmu_ownership(PMU_OWNER_HVM) )
> +        if ( IS_ENABLED(CONFIG_XENOPROF) &&
> +             !acquire_pmu_ownership(PMU_OWNER_HVM) )
>              return 0;
>          vpmu_set(vpmu, VPMU_RUNNING);
>  

Instead of modifying each caller into the oprofile code like this, I
wonder whether it would be neater to produce an empty set of static
inlines in xenoprof.h when !CONFIG_XENOPROF, similar to
CONFIG_SHADOW_PAGING in xen/include/asm-x86/shadow.h

~Andrew