diff options
Diffstat (limited to 'sys/dev/hwpmc/hwpmc_mod.c')
| -rw-r--r-- | sys/dev/hwpmc/hwpmc_mod.c | 50 |
1 files changed, 35 insertions, 15 deletions
diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c index 024a54f..7f46573 100644 --- a/sys/dev/hwpmc/hwpmc_mod.c +++ b/sys/dev/hwpmc/hwpmc_mod.c @@ -1282,8 +1282,16 @@ pmc_process_csw_in(struct thread *td) */ if (PMC_TO_MODE(pm) == PMC_MODE_TS) { mtx_pool_lock_spin(pmc_mtxpool, pm); + + /* + * Use the saved value calculated after the most recent + * thread switch out to start this counter. Reset + * the saved count in case another thread from this + * process switches in before any threads switch out. + */ newvalue = PMC_PCPU_SAVED(cpu,ri) = pp->pp_pmcs[ri].pp_pmcval; + pp->pp_pmcs[ri].pp_pmcval = pm->pm_sc.pm_reloadcount; mtx_pool_unlock_spin(pmc_mtxpool, pm); } else { KASSERT(PMC_TO_MODE(pm) == PMC_MODE_TC, @@ -1431,31 +1439,43 @@ pmc_process_csw_out(struct thread *td) pcd->pcd_read_pmc(cpu, adjri, &newvalue); - tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); - - PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd", cpu, ri, - tmp); - if (mode == PMC_MODE_TS) { + PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (samp)", + cpu, ri, PMC_PCPU_SAVED(cpu,ri) - newvalue); /* * For sampling process-virtual PMCs, - * we expect the count to be - * decreasing as the 'value' - * programmed into the PMC is the - * number of events to be seen till - * the next sampling interrupt. + * newvalue is the number of events to be seen + * until the next sampling interrupt. + * We can just add the events left from this + * invocation to the counter, then adjust + * in case we overflow our range. + * + * (Recall that we reload the counter every + * time we use it.) */ - if (tmp < 0) - tmp += pm->pm_sc.pm_reloadcount; mtx_pool_lock_spin(pmc_mtxpool, pm); - pp->pp_pmcs[ri].pp_pmcval -= tmp; - if ((int64_t) pp->pp_pmcs[ri].pp_pmcval <= 0) - pp->pp_pmcs[ri].pp_pmcval += + + pp->pp_pmcs[ri].pp_pmcval += newvalue; + if (pp->pp_pmcs[ri].pp_pmcval > + pm->pm_sc.pm_reloadcount) + pp->pp_pmcs[ri].pp_pmcval -= pm->pm_sc.pm_reloadcount; + KASSERT(pp->pp_pmcs[ri].pp_pmcval > 0 && + pp->pp_pmcs[ri].pp_pmcval <= + pm->pm_sc.pm_reloadcount, + ("[pmc,%d] pp_pmcval outside of expected " + "range cpu=%d ri=%d pp_pmcval=%jx " + "pm_reloadcount=%jx", __LINE__, cpu, ri, + pp->pp_pmcs[ri].pp_pmcval, + pm->pm_sc.pm_reloadcount)); mtx_pool_unlock_spin(pmc_mtxpool, pm); } else { + tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); + + PMCDBG3(CSW,SWO,1,"cpu=%d ri=%d tmp=%jd (count)", + cpu, ri, tmp); /* * For counting process-virtual PMCs, |
