perf inject: Do not load map/dso when injecting build-id
No need to load symbols in a DSO when injecting build-id. I guess the reason was to check the DSO is a special file like anon files. Use some helper functions in map.c to check them before reading build-id. Also pass sample event's cpumode to a new build-id event. It brought a speedup in the benchmark of 25 -> 21 msec on my laptop. Also the memory usage (Max RSS) went down by ~200 KB. # Running 'internals/inject-build-id' benchmark: Average build-id injection took: 21.389 msec (+- 0.138 msec) Average time per event: 2.097 usec (+- 0.014 usec) Average memory usage: 8225 KB (+- 0 KB) Committer notes: Before: $ perf stat -r5 perf bench internals inject-build-id > /dev/null Performance counter stats for 'perf bench internals inject-build-id' (5 runs): 4,020.56 msec task-clock:u # 1.271 CPUs utilized ( +- 0.74% ) 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 123,354 page-faults:u # 0.031 M/sec ( +- 0.81% ) 7,119,951,568 cycles:u # 1.771 GHz ( +- 1.74% ) (83.27%) 230,086,969 stalled-cycles-frontend:u # 3.23% frontend cycles idle ( +- 1.97% ) (83.41%) 1,168,298,765 stalled-cycles-backend:u # 16.41% backend cycles idle ( +- 1.13% ) (83.44%) 11,173,083,669 instructions:u # 1.57 insn per cycle # 0.10 stalled cycles per insn ( +- 1.58% ) (83.31%) 2,413,908,936 branches:u # 600.392 M/sec ( +- 1.69% ) (83.26%) 46,576,289 branch-misses:u # 1.93% of all branches ( +- 2.20% ) (83.31%) 3.1638 +- 0.0309 seconds time elapsed ( +- 0.98% ) $ After: $ perf stat -r5 perf bench internals inject-build-id > /dev/null Performance counter stats for 'perf bench internals inject-build-id' (5 runs): 2,379.94 msec task-clock:u # 1.473 CPUs utilized ( +- 0.18% ) 0 context-switches:u # 0.000 K/sec 0 cpu-migrations:u # 0.000 K/sec 62,584 page-faults:u # 0.026 M/sec ( +- 0.07% ) 2,372,389,668 cycles:u # 0.997 GHz ( +- 0.29% ) (83.14%) 106,937,862 stalled-cycles-frontend:u # 4.51% frontend cycles idle ( +- 4.89% ) (83.20%) 581,697,915 stalled-cycles-backend:u # 24.52% backend cycles idle ( +- 0.71% ) (83.47%) 3,659,692,199 instructions:u # 1.54 insn per cycle # 0.16 stalled cycles per insn ( +- 0.10% ) (83.63%) 791,372,961 branches:u # 332.518 M/sec ( +- 0.27% ) (83.39%) 10,648,083 branch-misses:u # 1.35% of all branches ( +- 0.22% ) (83.16%) 1.61570 +- 0.00172 seconds time elapsed ( +- 0.11% ) $ Signed-off-by:Namhyung Kim <namhyung@kernel.org> Original-patch-by:
Stephane Eranian <eranian@google.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by:
Jiri Olsa <jolsa@redhat.com> Link: https://lore.kernel.org/r/20201012070214.2074921-5-namhyung@kernel.org Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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