xref: /linux/Documentation/admin-guide/perf/mrvl-odyssey-tad-pmu.rst (revision 9ad09c4f2868540130ad2d5dfe265f55c75c1705)
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2Marvell Odyssey LLC-TAD Performance Monitoring Unit (PMU UNCORE)
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4
5Each TAD provides eight 64-bit counters for monitoring
6cache behavior.The driver always configures the same counter for
7all the TADs. The user would end up effectively reserving one of
8eight counters in every TAD to look across all TADs.
9The occurrences of events are aggregated and presented to the user
10at the end of running the workload. The driver does not provide a
11way for the user to partition TADs so that different TADs are used for
12different applications.
13
14The performance events reflect various internal or interface activities.
15By combining the values from multiple performance counters, cache
16performance can be measured in terms such as: cache miss rate, cache
17allocations, interface retry rate, internal resource occupancy, etc.
18
19The PMU driver exposes the available events and format options under sysfs::
20
21        /sys/bus/event_source/devices/tad/events/
22        /sys/bus/event_source/devices/tad/format/
23
24Examples::
25
26   $ perf list | grep tad
27        tad/tad_alloc_any/                                 [Kernel PMU event]
28        tad/tad_alloc_dtg/                                 [Kernel PMU event]
29        tad/tad_alloc_ltg/                                 [Kernel PMU event]
30        tad/tad_hit_any/                                   [Kernel PMU event]
31        tad/tad_hit_dtg/                                   [Kernel PMU event]
32        tad/tad_hit_ltg/                                   [Kernel PMU event]
33        tad/tad_req_msh_in_exlmn/                          [Kernel PMU event]
34        tad/tad_tag_rd/                                    [Kernel PMU event]
35        tad/tad_tot_cycle/                                 [Kernel PMU event]
36
37   $ perf stat -e tad_alloc_dtg,tad_alloc_ltg,tad_alloc_any,tad_hit_dtg,tad_hit_ltg,tad_hit_any,tad_tag_rd <workload>
38