Messages in this thread | | | Date | Tue, 14 May 2013 09:14:24 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/2] IOMMU/AMD: IOMMU PC PERF uncore PMU implementation |
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On Mon, May 13, 2013 at 04:44:13PM -0500, steven.kinney@amd.com wrote: > From: Steven L Kinney <Steven.Kinney@amd.com> > > Implement a perf PMU to handle IOMMU PC perf events. This PMU will handle > static counter perf events relative to the AMD IOMMU Performance Counters. > > To invoke the AMD IOMMU PMU issue a perf tool command such as: > > ./perf stat -e amd_iommu/config=<config-data>,config1=<config1-data>/u <command> > > For example: > > ./perf stat -e amd_iommu/config=0x8000000000000005,config1=0/u <command> > > The resulting count will be how many IOMMU total peripheral memory > operations were performed during the command execution window. > > Signed-off-by: Steven Kinney <steven.kinney@amd.com> > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> > ---
> +PMU_FORMAT_ATTR(iommu_raw, "config:63");
> +static int perf_iommu_init(struct perf_event *event) > +{ > + struct hw_perf_event *hwc = &event->hw; > + struct perf_iommu *perf_iommu; > + u64 config, config1; > + > + /* initialize the cntr_assign_mask */ > + cntr_assign_mask = 0; > + > + /* test the event attr type check for PMU enumeration */ > + if (event->attr.type != event->pmu->type) > + return -ENOENT; > + > + perf_iommu = &perf_iommu_fetch; > + > + if (perf_iommu) { > + config = event->attr.config; > + config1 = event->attr.config1; > + } else > + return -EINVAL; > + > + if (event->pmu != &perf_iommu->pmu) > + return -ENOENT; > + > + /* make sure the event->attr.config is raw (vendor specific) */ > + if (!(config & IOMMU_PC_RAW_CONFIG_MASK)) > + return -EINVAL;
Is this really needed? Non of the uncore PMU drivers have a magic config bit either. Seems weird to me.
> + /* integrate with iommu base devid (0000), assume one iommu */ > + perf_iommu->max_banks = > + amd_iommu_pc_get_max_banks(IOMMU_BASE_DEVID); > + perf_iommu->max_counters = > + amd_iommu_pc_get_max_counters(IOMMU_BASE_DEVID); > + > + /* update the hw_perf_event struct with the iommu config data */ > + hwc->config = config; > + hwc->extra_reg.config = config1; > + > + return 0; > +}
Also it might make sense to add a few event aliases to both this IOMMU and the AMD uncore driver.
Search for uncore_.*_events in arch/x86/kernel/cpu/perf_event_intel_uncore.c for examples.
This way you can also make the IOMMU a tad more useful by providing some events you think are the most useful for people interested in this thing.
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