mirror of
https://github.com/torvalds/linux.git
synced 2024-11-26 14:12:06 +00:00
51d0bf99b8
When generating callstack information from branch_stack(Intel LBR), the actual number of callstack entry should be bigger than the number of branch_stack, for example: branch_stack records: B() -> C() A() -> B() converted callstack records should be: C() B() A() though, the number of callstack equals to the number of branch stack plus 1. This patch fixes above issue in branch_stack__printf(). For example, # echo 'scale=2000; 4*a(1)' > cmd # perf record --call-graph lbr bc -l < cmd Before applying this patch, `perf script -D` output: 1220022677386876 0x2a40 [0xd8]: PERF_RECORD_SAMPLE(IP, 0x4002): 17990/17990: 0x40a6d6 period: 894172 addr: 0 ... LBR call chain: nr:8 ..... 0: fffffffffffffe00 ..... 1: 000000000040a410 ..... 2: 000000000040573c ..... 3: 0000000000408650 ..... 4: 00000000004022f2 ..... 5: 00000000004015f5 ..... 6: 00007f5ed6dcb553 ..... 7: 0000000000401698 ... FP chain: nr:2 ..... 0: fffffffffffffe00 ..... 1: 000000000040a6d8 ... branch callstack: nr:6 # which is not consistent with LBR records. ..... 0: 000000000040a410 ..... 1: 0000000000408650 # ditto ..... 2: 00000000004022f2 ..... 3: 00000000004015f5 ..... 4: 00007f5ed6dcb553 ..... 5: 0000000000401698 ... thread: bc:17990 ...... dso: /usr/bin/bc bc 17990 1220022.677386: 894172 cycles: 40a410 [unknown] (/usr/bin/bc) 40573c [unknown] (/usr/bin/bc) 408650 [unknown] (/usr/bin/bc) 4022f2 [unknown] (/usr/bin/bc) 4015f5 [unknown] (/usr/bin/bc) 7f5ed6dcb553 __libc_start_main+0xf3 (/usr/lib64/libc-2.17.so) 401698 [unknown] (/usr/bin/bc) After applied: 1220022677386876 0x2a40 [0xd8]: PERF_RECORD_SAMPLE(IP, 0x4002): 17990/17990: 0x40a6d6 period: 894172 addr: 0 ... LBR call chain: nr:8 ..... 0: fffffffffffffe00 ..... 1: 000000000040a410 ..... 2: 000000000040573c ..... 3: 0000000000408650 ..... 4: 00000000004022f2 ..... 5: 00000000004015f5 ..... 6: 00007f5ed6dcb553 ..... 7: 0000000000401698 ... FP chain: nr:2 ..... 0: fffffffffffffe00 ..... 1: 000000000040a6d8 ... branch callstack: nr:7 ..... 0: 000000000040a410 ..... 1: 000000000040573c ..... 2: 0000000000408650 ..... 3: 00000000004022f2 ..... 4: 00000000004015f5 ..... 5: 00007f5ed6dcb553 ..... 6: 0000000000401698 ... thread: bc:17990 ...... dso: /usr/bin/bc bc 17990 1220022.677386: 894172 cycles: 40a410 [unknown] (/usr/bin/bc) 40573c [unknown] (/usr/bin/bc) 408650 [unknown] (/usr/bin/bc) 4022f2 [unknown] (/usr/bin/bc) 4015f5 [unknown] (/usr/bin/bc) 7f5ed6dcb553 __libc_start_main+0xf3 (/usr/lib64/libc-2.17.so) 401698 [unknown] (/usr/bin/bc) Change from v1: - refined code style according to Jiri's review comments. Signed-off-by: Chengdong Li <chengdongli@tencent.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: German Gomez <german.gomez@arm.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: likexu@tencent.com Link: https://lore.kernel.org/r/20220517015726.96131-1-chengdongli@tencent.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
---|---|---|
.. | ||
arch | ||
bench | ||
dlfilters | ||
Documentation | ||
examples/bpf | ||
include | ||
jvmti | ||
pmu-events | ||
python | ||
scripts | ||
tests | ||
trace | ||
ui | ||
util | ||
.gitignore | ||
Build | ||
builtin-annotate.c | ||
builtin-bench.c | ||
builtin-buildid-cache.c | ||
builtin-buildid-list.c | ||
builtin-c2c.c | ||
builtin-config.c | ||
builtin-daemon.c | ||
builtin-data.c | ||
builtin-diff.c | ||
builtin-evlist.c | ||
builtin-ftrace.c | ||
builtin-help.c | ||
builtin-inject.c | ||
builtin-kallsyms.c | ||
builtin-kmem.c | ||
builtin-kvm.c | ||
builtin-list.c | ||
builtin-lock.c | ||
builtin-mem.c | ||
builtin-probe.c | ||
builtin-record.c | ||
builtin-report.c | ||
builtin-sched.c | ||
builtin-script.c | ||
builtin-stat.c | ||
builtin-timechart.c | ||
builtin-top.c | ||
builtin-trace.c | ||
builtin-version.c | ||
builtin.h | ||
check-headers.sh | ||
command-list.txt | ||
CREDITS | ||
design.txt | ||
Makefile | ||
Makefile.config | ||
Makefile.perf | ||
MANIFEST | ||
perf-archive.sh | ||
perf-completion.sh | ||
perf-iostat.sh | ||
perf-read-vdso.c | ||
perf-sys.h | ||
perf-with-kcore.sh | ||
perf.c | ||
perf.h |