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

[Eric Dumazet]

Andi Kleen a écrit :
> >  			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? 


In my testings, the "if (CTR_OVERFLOWED())" condition is always true.

(I am profiling one event only)

I felt uncomfortable issuing the apic_write() before oprofile_add_sample()

Do you mean doing the apic_write() right at the beginning of the ppro_check_ctrs()
function ?

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