make_legacy_cache.py

  1#!/usr/bin/env python3
  2# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
  3import json
  4
  5hw_cache_id = [
  6    (0, # PERF_COUNT_HW_CACHE_L1D
  7     ["L1-dcache",  "l1-d",     "l1d",      "L1-data",],
  8     [0, 1, 2,], # read, write, prefetch
  9     "Level 1 data cache",
 10     ),
 11    (1, # PERF_COUNT_HW_CACHE_L1I
 12     ["L1-icache",  "l1-i",     "l1i",      "L1-instruction",],
 13     [0, 2,], # read, prefetch
 14     "Level 1 instruction cache",
 15     ),
 16    (2, # PERF_COUNT_HW_CACHE_LL
 17     ["LLC", "L2"],
 18     [0, 1, 2,], # read, write, prefetch
 19     "Last level cache",
 20     ),
 21    (3, # PERF_COUNT_HW_CACHE_DTLB
 22     ["dTLB",   "d-tlb",    "Data-TLB",],
 23     [0, 1, 2,], # read, write, prefetch
 24     "Data TLB",
 25     ),
 26    (4, # PERF_COUNT_HW_CACHE_ITLB
 27     ["iTLB",   "i-tlb",    "Instruction-TLB",],
 28     [0,], # read
 29     "Instruction TLB",
 30     ),
 31    (5, # PERF_COUNT_HW_CACHE_BPU
 32     ["branch", "branches", "bpu",      "btb",      "bpc",],
 33     [0,], # read
 34     "Branch prediction unit",
 35     ),
 36    (6, # PERF_COUNT_HW_CACHE_NODE
 37     ["node",],
 38     [0, 1, 2,], # read, write, prefetch
 39     "Local memory",
 40     ),
 41]
 42
 43hw_cache_op = [
 44    (0, # PERF_COUNT_HW_CACHE_OP_READ
 45     ["load",   "loads",    "read",],
 46     "read"),
 47    (1, # PERF_COUNT_HW_CACHE_OP_WRITE
 48     ["store",  "stores",   "write",],
 49     "write"),
 50    (2, # PERF_COUNT_HW_CACHE_OP_PREFETCH
 51     ["prefetch",   "prefetches",   "speculative-read", "speculative-load",],
 52     "prefetch"),
 53]
 54
 55hw_cache_result = [
 56    (0, # PERF_COUNT_HW_CACHE_RESULT_ACCESS
 57     ["refs",   "Reference",    "ops",      "access",],
 58     "accesses"),
 59    (1, # PERF_COUNT_HW_CACHE_RESULT_MISS
 60     ["misses", "miss",],
 61     "misses"),
 62]
 63
 64events = []
 65def add_event(name: str,
 66              cache_id: int, cache_op: int, cache_result: int,
 67              desc: str,
 68              deprecated: bool) -> None:
 69    # Avoid conflicts with PERF_TYPE_HARDWARE events which are higher priority.
 70    if name in ["branch-misses", "branches"]:
 71        return
 72
 73    # Tweak and deprecate L2 named events.
 74    if name.startswith("L2"):
 75        desc = desc.replace("Last level cache", "Level 2 (or higher) last level cache")
 76        deprecated = True
 77
 78    event = {
 79        "EventName": name,
 80        "BriefDescription": desc,
 81        "LegacyCacheCode": f"0x{cache_id | (cache_op << 8) | (cache_result << 16):06x}",
 82    }
 83
 84    # Deprecate events with the name starting L2 as it is actively
 85    # confusing as on many machines it actually means the L3 cache.
 86    if deprecated:
 87        event["Deprecated"] = "1"
 88    events.append(event)
 89
 90for (cache_id, names, ops, cache_desc) in hw_cache_id:
 91    for name in names:
 92        add_event(name,
 93                  cache_id,
 94                  0, # PERF_COUNT_HW_CACHE_OP_READ
 95                  0, # PERF_COUNT_HW_CACHE_RESULT_ACCESS
 96                  f"{cache_desc} read accesses.",
 97                  deprecated=True)
 98
 99        for (op, op_names, op_desc) in hw_cache_op:
100            if op not in ops:
101                continue
102            for op_name in op_names:
103                deprecated = (names[0] != name or op_names[1] != op_name)
104                add_event(f"{name}-{op_name}",
105                          cache_id,
106                          op,
107                          0, # PERF_COUNT_HW_CACHE_RESULT_ACCESS
108                          f"{cache_desc} {op_desc} accesses.",
109                          deprecated)
110
111                for (result,  result_names, result_desc) in hw_cache_result:
112                    for result_name in result_names:
113                        deprecated = ((names[0] != name or op_names[0] != op_name) or
114                                      (result == 0) or (result_names[0] != result_name))
115                        add_event(f"{name}-{op_name}-{result_name}",
116                                  cache_id, op, result,
117                                  f"{cache_desc} {op_desc} {result_desc}.",
118                                  deprecated)
119
120        for (result,  result_names, result_desc) in hw_cache_result:
121            for result_name in result_names:
122                add_event(f"{name}-{result_name}",
123                          cache_id,
124                          0, # PERF_COUNT_HW_CACHE_OP_READ
125                          result,
126                          f"{cache_desc} read {result_desc}.",
127                          deprecated=True)
128
129print(json.dumps(events, indent=2))