On 2016-01-22 01:15, 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. > > 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 cc97f08..f765b2c 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)
The 2nd arg "id" is not necessary. -- Seiichi
