On Wed, 11 Mar 2015 16:25:52 -0500 kazutomo <[email protected]> wrote:
> Hi Jacob, > > Wow, this is a really pitfall for people who are writing their own > RAPL tool. > Anyway, I've tested your patch on a Haswell system (2699v3), running a > dgemm > benchmark. NOTE: userspace governor is selected. All core are set to > 2.3 GHz. > No power cap is set. > > # before the patch is applied > $ cd /sys/class/powercap/intel-rapl:0:0 > $ cat name > dram > $ for i in 1 2 3 ; do a=`cat energy_uj` ; sleep 1 ; b=`cat > energy_uj` ; expr $b - $a ; done > 16853445 > 16829355 > 16666320 > > # after the patch is applied > $ for i in 1 2 3 ; do a=`cat energy_uj` ; sleep 1 ; b=`cat > energy_uj` ; expr $b - $a ; done > 69751487 > 68153897 > 69689816 > thanks for testing, but i thought the results should be the other way around. counting 15uJ vs 61uJ after the patch is applied. I will double check once i get a machine again. > > I have a couple of questions. > > 1. Is it possible to retrieve the DRAM energy unit from some MSRs > *eventually* like the domain energy unit? > according to the document, future DRAM energy unit will always be hardcoded to 15.3uJ, no enumeration since there is no domain specific MSR for energy unit. > 2. Will the Intel software developer's manual (vol3b) be updated > accordingly if you know? I'm assuming that you are working at Intel. > I don't know. Let me get back to you later. > 3. Is get_max_energy_range_uj still the same as other counters? > good catch. max energy is obtained from parent package domain which still uses MSR enumerated unit. now it has to be per domain. > 4. The current driver maintains the unit as an integer, instead of a > shift value, and the multiplier is a relatively small number. I guess > the DRAM energy unit is technically ~15.2587 uJ = (0.5 ** 16) * 1e6, > so it always reports a approx. 2 % smaller energy number, while the > pkg energy unit is ~61.0351, so the error is ~0.5 %. An easier > solution would be to maintain the unit in pJ, instead of uJ. > or am I worrying too much? I guess the RAPL energy estimation may > have some error, so maybe canceling out. > yes, you are right. using pJ or more precise shift would be a better. let me add that also. Thanks, Jacob > - kaz > > On 03/11/2015 07:55 AM, Jacob Pan wrote: > > The current driver assumes all RAPL domains within a CPU package > > have the same energy unit. This is no longer true for HSW server > > CPUs since DRAM domain has is own fixed energy unit which can be > > different than the package energy unit enumerated by package > > power MSR. In fact, the default HSW EP package power unit is 61uJ > > whereas DRAM domain unit is 15.3uJ. The result is that DRAM power > > consumption is counted 4x more than real power reported by energy > > counters. > > > > This patch adds domain specific energy unit per cpu type, it allows > > domain energy unit to override package energy unit if non zero. > > > > Signed-off-by: Jacob Pan <[email protected]> > > --- > > drivers/powercap/intel_rapl.c | 35 > > ++++++++++++++++++++++++++++------- 1 file changed, 28 > > insertions(+), 7 deletions(-) > > > > diff --git a/drivers/powercap/intel_rapl.c > > b/drivers/powercap/intel_rapl.c index 97b5e4e..af4c61e 100644 > > --- a/drivers/powercap/intel_rapl.c > > +++ b/drivers/powercap/intel_rapl.c > > @@ -158,6 +158,7 @@ struct rapl_domain { > > struct rapl_power_limit rpl[NR_POWER_LIMITS]; > > u64 attr_map; /* track capabilities */ > > unsigned int state; > > + unsigned int domain_energy_unit; > > int package_id; > > }; > > #define power_zone_to_rapl_domain(_zone) \ > > @@ -190,6 +191,7 @@ struct rapl_defaults { > > void (*set_floor_freq)(struct rapl_domain *rd, bool mode); > > u64 (*compute_time_window)(struct rapl_package *rp, u64 > > val, bool to_raw); > > + unsigned int dram_domain_energy_unit; > > }; > > static struct rapl_defaults *rapl_defaults; > > > > @@ -227,7 +229,8 @@ static int rapl_read_data_raw(struct > > rapl_domain *rd, static int rapl_write_data_raw(struct rapl_domain > > *rd, enum rapl_primitives prim, > > unsigned long long value); > > -static u64 rapl_unit_xlate(int package, enum unit_type type, u64 > > value, +static u64 rapl_unit_xlate(struct rapl_domain *rd, int > > package, > > + enum unit_type type, u64 value, > > int to_raw); > > static void package_power_limit_irq_save(int package_id); > > > > @@ -305,7 +308,8 @@ static int get_energy_counter(struct > > powercap_zone *power_zone, u64 *energy_raw) > > static int get_max_energy_counter(struct powercap_zone *pcd_dev, > > u64 *energy) { > > - *energy = rapl_unit_xlate(0, ENERGY_UNIT, > > ENERGY_STATUS_MASK, 0); > > + /* package domain is the largest */ > > + *energy = rapl_unit_xlate(NULL, 0, ENERGY_UNIT, > > ENERGY_STATUS_MASK, 0); return 0; > > } > > > > @@ -639,6 +643,11 @@ static void rapl_init_domains(struct > > rapl_package *rp) rd->msrs[4] = MSR_DRAM_POWER_INFO; > > rd->rpl[0].prim_id = PL1_ENABLE; > > rd->rpl[0].name = pl1_name; > > + rd->domain_energy_unit = > > + > > rapl_defaults->dram_domain_energy_unit; > > + if (rd->domain_energy_unit) > > + pr_info("DRAM domain energy unit > > %duj\n", > > + rd->domain_energy_unit); > > break; > > } > > if (mask) { > > @@ -648,7 +657,8 @@ static void rapl_init_domains(struct > > rapl_package *rp) } > > } > > > > -static u64 rapl_unit_xlate(int package, enum unit_type type, u64 > > value, +static u64 rapl_unit_xlate(struct rapl_domain *rd, int > > package, > > + enum unit_type type, u64 value, > > int to_raw) > > { > > u64 units = 1; > > @@ -663,7 +673,11 @@ static u64 rapl_unit_xlate(int package, enum > > unit_type type, u64 value, units = rp->power_unit; > > break; > > case ENERGY_UNIT: > > - units = rp->energy_unit; > > + /* per domain unit takes precedence */ > > + if (rd && rd->domain_energy_unit) > > + units = rd->domain_energy_unit; > > + else > > + units = rp->energy_unit; > > break; > > case TIME_UNIT: > > return rapl_defaults->compute_time_window(rp, > > value, to_raw); @@ -773,7 +787,7 @@ static int > > rapl_read_data_raw(struct rapl_domain *rd, final = value & rp->mask; > > final = final >> rp->shift; > > if (xlate) > > - *data = rapl_unit_xlate(rd->package_id, rp->unit, > > final, 0); > > + *data = rapl_unit_xlate(rd, rd->package_id, > > rp->unit, final, 0); else > > *data = final; > > > > @@ -799,7 +813,7 @@ static int rapl_write_data_raw(struct > > rapl_domain *rd, "failed to read msr 0x%x on cpu %d\n", msr, cpu); > > return -EIO; > > } > > - value = rapl_unit_xlate(rd->package_id, rp->unit, value, > > 1); > > + value = rapl_unit_xlate(rd, rd->package_id, rp->unit, > > value, 1); msr_val &= ~rp->mask; > > msr_val |= value << rp->shift; > > if (wrmsrl_safe_on_cpu(cpu, msr, msr_val)) { > > @@ -1017,6 +1031,13 @@ static const struct rapl_defaults > > rapl_defaults_core = { .compute_time_window = > > rapl_compute_time_window_core, }; > > > > +static const struct rapl_defaults rapl_defaults_hsw_server = { > > + .check_unit = rapl_check_unit_core, > > + .set_floor_freq = set_floor_freq_default, > > + .compute_time_window = rapl_compute_time_window_core, > > + .dram_domain_energy_unit = 15, > > +}; > > + > > static const struct rapl_defaults rapl_defaults_atom = { > > .check_unit = rapl_check_unit_atom, > > .set_floor_freq = set_floor_freq_atom, > > @@ -1037,7 +1058,7 @@ static const struct x86_cpu_id rapl_ids[] = { > > RAPL_CPU(0x3a, rapl_defaults_core),/* Ivy Bridge */ > > RAPL_CPU(0x3c, rapl_defaults_core),/* Haswell */ > > RAPL_CPU(0x3d, rapl_defaults_core),/* Broadwell */ > > - RAPL_CPU(0x3f, rapl_defaults_core),/* Haswell */ > > + RAPL_CPU(0x3f, rapl_defaults_hsw_server),/* Haswell > > servers */ RAPL_CPU(0x45, rapl_defaults_core),/* Haswell ULT */ > > RAPL_CPU(0x4C, rapl_defaults_atom),/* Braswell */ > > RAPL_CPU(0x4A, rapl_defaults_atom),/* Tangier */ > [Jacob Pan] -- 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/
