[PATCH v4 0/8] perf mem/c2c: Add support for AMD (tools changes)

[Ravi Bangoria]

Kernel side of changes are already present in tip/perf/core except
one patch to rename PERF_MEM_LVLNUM_EXTN_MEM to PERF_MEM_LVLNUM_CXL[1].

Original description:

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[2], 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 top of acme/perf/core (3b1913adb188)

v3: https://lore.kernel.org/lkml/20220928095805.596-1-ravi.bangoria@xxxxxxx
v3->v4:
 - Rename PERF_MEM_LVLNUM_EXTN_MEM to PERF_MEM_LVLNUM_CXL for tools part.

[1]: https://lore.kernel.org/lkml/f6268268-b4e9-9ed6-0453-65792644d953@xxxxxxx
[2]: https://lore.kernel.org/lkml/20220829113347.295-1-ravi.bangoria@xxxxxxx


Ravi Bangoria (8):
  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_{CXL|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: Print "LFB/MAB" for PERF_MEM_LVLNUM_LFB
  perf script: Add missing fields in usage hint

 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 +++++++------
 10 files changed, 77 insertions(+), 18 deletions(-)

-- 
2.37.3