Hi Peter, > -----Original Message----- > From: Peter Zijlstra [mailto:[email protected]] > Sent: 19 августа 2015 г. 1:12 > To: Alexey Brodkin > Cc: [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; Arnaldo Carvalho de Melo > Subject: Re: [PATCH v2 4/8] ARCv2: perf: Support sampling events using > overflow interrupts > > On Wed, Aug 05, 2015 at 06:13:30PM +0300, Alexey Brodkin wrote: > > @@ -319,6 +336,20 @@ static int arc_pmu_add(struct perf_event *event, int > > flags) > > } > > > > write_aux_reg(ARC_REG_PCT_INDEX, idx); > > + > > + arc_pmu->act_counter[idx] = event; > > + > > + if (is_sampling_event(event)) { > > + /* Mimic full counter overflow as other arches do */ > > + write_aux_reg(ARC_REG_PCT_INT_CNTL, (u32)arc_pmu->max_period); > > + write_aux_reg(ARC_REG_PCT_INT_CNTH, > > + (arc_pmu->max_period >> 32)); > > + > > + /* Enable interrupt for this counter */ > > + write_aux_reg(ARC_REG_PCT_INT_CTRL, > > + read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx)); > > + } > > *confused* pmu::add should only start on flags & PERF_EF_START, and then > we start with hwc->sample_period, not the max_period.
Did you mean here that we should enable interrupts in arc_pmu_start() but not in arc_pmu_add()? -Alexey -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
