Messages in this thread | | | From | Ravi Bangoria <> | Subject | [PATCH v3 00/15] perf mem/c2c: Add support for AMD | Date | Wed, 28 Sep 2022 15:27:50 +0530 |
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Perf mem and c2c tools are wrappers around perf record with mem load/ store events. IBS tagged load/store sample provides most of the information needed for these tools. Enable support for these tools on AMD Zen processors based on IBS Op pmu.
There are some limitations though: Only load/store micro-ops provide mem/c2c information. Whereas, IBS does not have a way to choose a particular type of micro-op to tag. This results in many non-LS micro-ops being tagged which appear as N/A in the perf report. IBS, being an uncore pmu from kernel point of view[1], does not support per process monitoring. Thus, perf mem/c2c on AMD are currently supported in per-cpu mode only.
Example: $ sudo ./perf mem record -- -c 10000 ^C[ perf record: Woken up 227 times to write data ] [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ]
$ sudo ./perf mem report -F mem,sample,snoop Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762 Memory access Samples Snoop N/A 700620 N/A L1 hit 126675 N/A L2 hit 424 N/A L3 hit 664 HitM L3 hit 10 N/A Local RAM hit 2 N/A Remote RAM (1 hop) hit 8558 N/A Remote Cache (1 hop) hit 3 N/A Remote Cache (1 hop) hit 2 HitM Remote Cache (2 hops) hit 10 HitM Remote Cache (2 hops) hit 6 N/A Uncached hit 4 N/A
Prepared on queue/perf/core (cce6a2d7e0e49).
v2: https://lore.kernel.org/all/20220616113638.900-1-ravi.bangoria@amd.com v2->v3: - Use sample_flags instead of __PERF_SAMPLE_*_EARLY varients - Make PERF_SAMPLE_WEIGHT independent of PERF_SAMPLE_DATA_SRC - Add a patch to reverse sync PERF_MEM_SNOOPX_PEER from tools to kernel uapi header - Add Acked-by: Jiri Olsa for tool side unchanged patches
Also, a recent patch[2] to test perf mem fails on AMD because of aforementioned limitations.
[1]: https://lore.kernel.org/lkml/20220829113347.295-1-ravi.bangoria@amd.com [2]: https://lore.kernel.org/lkml/20220924133408.1125903-1-leo.yan%40linaro.org
Ravi Bangoria (15): perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO} perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions perf/x86/amd: Support PERF_SAMPLE_DATA_SRC perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT} perf/x86/amd: Support PERF_SAMPLE_ADDR perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file perf tool: Sync include/uapi/linux/perf_event.h header perf tool: Sync arch/x86/include/asm/amd-ibs.h header perf mem: Add support for printing PERF_MEM_LVLNUM_{EXTN_MEM|IO} perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events perf mem/c2c: Add load store event mappings for AMD perf mem/c2c: Avoid printing empty lines for unsupported events perf mem: Use more generic term for LFB perf script: Add missing fields in usage hint
arch/x86/events/amd/ibs.c | 345 ++++++++++++++++++++++- arch/x86/include/asm/amd-ibs.h | 16 ++ include/uapi/linux/perf_event.h | 6 +- kernel/events/core.c | 3 +- tools/arch/x86/include/asm/amd-ibs.h | 16 ++ tools/include/uapi/linux/perf_event.h | 4 +- tools/perf/Documentation/perf-c2c.txt | 14 +- tools/perf/Documentation/perf-mem.txt | 3 +- tools/perf/Documentation/perf-record.txt | 1 + tools/perf/arch/x86/util/mem-events.c | 31 +- tools/perf/builtin-c2c.c | 1 + tools/perf/builtin-mem.c | 1 + tools/perf/builtin-script.c | 7 +- tools/perf/util/mem-events.c | 17 +- 14 files changed, 438 insertions(+), 27 deletions(-)
-- 2.31.1
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