Akshay Adiga <akshay.ad...@linux.vnet.ibm.com> writes: > Iozone results show fairly consistent performance boost. > YCSB on redis shows improved Max latencies in most cases.
What about power consumption? > Iozone write/rewite test were made with filesizes 200704Kb and 401408Kb > with different record sizes . The following table shows IOoperations/sec > with and without patch. > Iozone Results ( in op/sec) ( mean over 3 iterations ) What's the variance between runs? > Tested with YCSB workload (50% update + 50% read) over redis for 1 million > records and 1 million operation. Each test was carried out with target > operations per second and persistence disabled. > > Max-latency (in us)( mean over 5 iterations ) What's the variance between runs? std dev? 95th percentile? > --------------------------------------------------------------- > op/s Operation with patch without patch %change > --------------------------------------------------------------- > 15000 Read 61480.6 50261.4 22.32 This seems fairly significant regression. Any idea why at 15K op/s there's such a regression? > --- a/drivers/cpufreq/powernv-cpufreq.c > +++ b/drivers/cpufreq/powernv-cpufreq.c [ 15 more citation lines. Click/Enter to show. ] > @@ -36,12 +36,56 @@ > #include <asm/reg.h> > #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */ > #include <asm/opal.h> > +#include <linux/timer.h> > > #define POWERNV_MAX_PSTATES 256 > #define PMSR_PSAFE_ENABLE (1UL << 30) > #define PMSR_SPR_EM_DISABLE (1UL << 31) > #define PMSR_MAX(x) ((x >> 32) & 0xFF) > > +#define MAX_RAMP_DOWN_TIME 5120 > +/* > + * On an idle system we want the global pstate to ramp-down from max value > to > + * min over a span of ~5 secs. Also we want it to initially ramp-down > slowly and > + * then ramp-down rapidly later on. Where does 5 seconds come from? Why 5 and not 10, or not 2? Is there some time period inherit in hardware or software that this is computed from? > +/* Interval after which the timer is queued to bring down global pstate */ > +#define GPSTATE_TIMER_INTERVAL 2000 in ms? -- Stewart Smith OPAL Architect, IBM. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
