Re: [PATCH] oprofile: re-arm APIC_DM_NMI in ppro_check_ctrs()

[Andi Kleen <andi@firstfloor.org>]

>  			oprofile_add_sample(regs, i);
> +			/*
> +			 * We need to unmask the apic vector *before*
> +			 * writing reset_value to msr counter
> +			 */
> +			apic_write(APIC_LVTPC, APIC_DM_NMI);
>  			wrmsrl(msrs->counters[i].addr, -reset_value[i]);
>  		}
>  	}
>  
> -	/* Only P6 based Pentium M need to re-unmask the apic vector but it
> -	 * doesn't hurt other P6 variant */
> -	apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);

Did you also test if it really needs to be inside the if () or 
just before the wrmsrl? 

-Andi