On 03/31/2016 02:28 PM, Pandruvada, Srinivas wrote: > On Mon, 2016-03-21 at 08:27 -0400, Prarit Bhargava wrote: >> The MSR_PKG_POWER_INFO register (Intel ASDM, section 14.9.3 >> "Package RAPL Domain") provides a maximum time window which the >> system can support. This window is read-only and is currently >> not examined when setting the time windows for the package. >> > Usually this field has lot of junk. It is not supported uniformly. > The system provides this value from another ACPI element called PPCC. > If supported this will be in > > $ /sys/bus/pci/devices/0000:00:04.0/power_limits > $ grep . * > power_limit_0_max_uw:15000000 > power_limit_0_min_uw:125000 > power_limit_0_step_uw:1000000 > power_limit_0_tmax_us:32000000 > power_limit_0_tmin_us:28000000 > power_limit_1_max_uw:25000000 > power_limit_1_min_uw:25000000 > power_limit_1_step_uw:1000000 > power_limit_1_tmax_us:0 > power_limit_1_tmin_us:0 >
Interesting. I'll go and take a look on my test system to see if this is supported. P. > Thanks, > Srinivas >> This patch implements get_max_time_window_us() and checks the window >> when >> a user attempts to set power capping for the package. >> >> Before the patch it was possible to set the window to, for example, >> 10000 >> micro seconds: >> >> [root@intel-chiefriver-03 rhel7]# echo 10000 > >> /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl\:0/constraint_0_time_window_us; >> egrep ^ /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl\:0/constraint_0_time_window_us >> >> /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl:0/constraint_0_time_window_us:1:9765 >> >> but from 'turbostat -d', the package is limited to 976us: >> >> cpu0: MSR_PKG_POWER_INFO: 0x01200168 (45 W TDP, RAPL 36 - 0 W, >> 0.000977 sec.) >> >> (Note, there appears to be a rounding issue in turbostat which needs >> to >> also be fixed. Looking at the values in the register it is clear the >> value is 1/1024 = 976us.) >> >> After the patch we are limited by the maximum time window: >> >> [root@intel-chiefriver-03 rhel7]# echo 10000 > >> /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl\:0/constraint_0_time_window_us; >> egrep ^ /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl\:0/constraint_0_time_window_us >> >> -bash: echo: write error: Invalid argument >> /sys/devices/virtual/powercap/intel-rapl/intel- >> rapl:0/constraint_0_time_window_us:1:976 >> >> Cc: "Rafael J. Wysocki" <[email protected]> >> Cc: Prarit Bhargava <[email protected]> >> Cc: Radivoje Jovanovic <[email protected]> >> Cc: Seiichi Ikarashi <[email protected]> >> Cc: Mathias Krause <[email protected]> >> Cc: Ajay Thomas <[email protected]> >> Signed-off-by: Prarit Bhargava <[email protected]> >> --- >> drivers/powercap/intel_rapl.c | 31 >> +++++++++++++++++++++++++++++++ >> drivers/powercap/powercap_sys.c | 6 ++++-- >> 2 files changed, 35 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/powercap/intel_rapl.c >> b/drivers/powercap/intel_rapl.c >> index 6c592dc..feb063d 100644 >> --- a/drivers/powercap/intel_rapl.c >> +++ b/drivers/powercap/intel_rapl.c >> @@ -493,13 +493,42 @@ static int get_current_power_limit(struct >> powercap_zone *power_zone, int id, >> return ret; >> } >> >> +static int get_max_time_window(struct powercap_zone *power_zone, int >> id, >> + u64 *data) >> +{ >> + struct rapl_domain *rd; >> + int ret = 0; >> + u64 val; >> + >> + get_online_cpus(); >> + rd = power_zone_to_rapl_domain(power_zone); >> + >> + if (rapl_read_data_raw(rd, MAX_TIME_WINDOW, true, &val)) >> + ret = -EIO; >> + else >> + *data = val; >> + >> + put_online_cpus(); >> + return ret; >> +} >> + >> static int set_time_window(struct powercap_zone *power_zone, int id, >> u64 >> window) >> { >> struct rapl_domain *rd; >> int ret = 0; >> + u64 max_window; >> >> get_online_cpus(); >> + ret = get_max_time_window(power_zone, id, &max_window); >> + if (ret < 0) >> + goto out; >> + >> + if (window > max_window) { >> + ret = -EINVAL; >> + goto out; >> + } >> + >> rd = power_zone_to_rapl_domain(power_zone); >> switch (rd->rpl[id].prim_id) { >> case PL1_ENABLE: >> @@ -511,6 +540,7 @@ static int set_time_window(struct powercap_zone >> *power_zone, int id, >> default: >> ret = -EINVAL; >> } >> +out: >> put_online_cpus(); >> return ret; >> } >> @@ -590,6 +620,7 @@ static const struct powercap_zone_constraint_ops >> constraint_ops = { >> .set_time_window_us = set_time_window, >> .get_time_window_us = get_time_window, >> .get_max_power_uw = get_max_power, >> + .get_max_time_window_us = get_max_time_window, >> .get_name = get_constraint_name, >> }; >> >> diff --git a/drivers/powercap/powercap_sys.c >> b/drivers/powercap/powercap_sys.c >> index 14bde0d..53fad0f 100644 >> --- a/drivers/powercap/powercap_sys.c >> +++ b/drivers/powercap/powercap_sys.c >> @@ -101,7 +101,7 @@ static ssize_t store_constraint_##_attr(struct >> device *dev,\ >> int err; \ >> u64 value; \ >> struct powercap_zone *power_zone = to_powercap_zone(dev); \ >> - int id; \ >> + int id, ret; \ >> struct powercap_zone_constraint *pconst;\ >> \ >> if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \ >> @@ -113,8 +113,10 @@ static ssize_t store_constraint_##_attr(struct >> device *dev,\ >> if (err) \ >> return -EINVAL; \ >> if (pconst && pconst->ops && pconst->ops->set_##_attr) { \ >> - if (!pconst->ops->set_##_attr(power_zone, id, >> value)) \ >> + ret = pconst->ops->set_##_attr(power_zone, id, >> value); \ >> + if (!ret) \ >> return count; \ >> + return ret; \ >> } \ >> \ >> return -ENODATA; \
