Messages in this thread Patch in this message | | | Date | Mon, 10 Jan 2022 16:26:26 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v4 44/48] perf bpf: Rename cpu to cpu_map_idx |
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Em Mon, Jan 10, 2022 at 04:10:46PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Jan 04, 2022 at 10:13:47PM -0800, Ian Rogers escreveu: > > Synchronize the caller in evsel with the called function. > > Shorten 3 lines of code in bperf_read by using > > perf_cpu_map__for_each_cpu. > > This code is frequently using variables named cpu as cpu map indices, > > which doesn't matter as all CPUs are in the CPU map. It is strange in > > some cases the cpumap is used at all. > > CC /tmp/build/perf/builtin-stat.o > INSTALL trace_plugins > CC /tmp/build/perf/util/evlist.o > CC /tmp/build/perf/util/evsel.o > CC /tmp/build/perf/util/header.o > CC /tmp/build/perf/util/bpf_counter.o > CC /tmp/build/perf/util/bpf_counter_cgroup.o > CC /tmp/build/perf/util/bpf_ftrace.o > In file included from util/cpumap.h:8, > from util/bpf_counter.c:23: > util/bpf_counter.c: In function ‘bperf__read’: > /var/home/acme/git/perf/tools/lib/perf/include/perf/cpumap.h:27:20: error: comparison of integer expressions of different signedness: ‘__u32’ {aka ‘unsigned int’} and ‘int’ [-Werror=sign-compare] > 27 | (idx) < perf_cpu_map__nr(cpus); \ > | ^ > util/bpf_counter.c:626:25: note: in expansion of macro ‘perf_cpu_map__for_each_cpu’ > 626 | perf_cpu_map__for_each_cpu(cpu, j, all_cpu_map) { > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > util/bpf_counter.c:611:21: error: unused variable ‘num_cpu’ [-Werror=unused-variable] > 611 | __u32 i, j, num_cpu; > | ^~~~~~~ > cc1: all warnings being treated as errors > make[4]: *** [/var/home/acme/git/perf/tools/build/Makefile.build:96: /tmp/build/perf/util/bpf_counter.o] Error 1 > make[4]: *** Waiting for unfinished jobs.... > make[3]: *** [/var/home/acme/git/perf/tools/build/Makefile.build:139: util] Error 2 > make[2]: *** [Makefile.perf:665: /tmp/build/perf/perf-in.o] Error 2 > make[1]: *** [Makefile.perf:240: sub-make] Error 2 > make: *** [Makefile:113: install-bin] Error 2 > make: Leaving directory '/var/home/acme/git/perf/tools/perf' > > Performance counter stats for 'make -k BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3 O=/tmp/build/perf -C tools/perf install-bin': > > 15,589,752,360 cycles:u > 28,227,862,710 instructions:u # 1.81 insn per cycle > > 1.996638375 seconds time elapsed > > 3.567457000 seconds user > 0.934840000 seconds sys > > > ⬢[acme@toolbox perf]$ git log --oneline -1 > 0083ba4c6a931fd0 (HEAD) perf bpf: Rename cpu to cpu_map_idx > ⬢[acme@toolbox perf]$ > > Trying to fix...
Would be better to have the "Shorten 3 lines of code in bperf_read by using perf_cpu_map__for_each_cpu." in a separate patch, try to do this next time.
Below cures the two issues.
- Arnaldo
Committer notes:
Found when building with BUILD_BPF_SKEL=1:
Remove unused 'num_cpu' variable in bperf__read().
Make 'j' an 'int' as it is used in perf_cpu_map__for_each_cpu() to compare against an 'int'
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c index ae5bd87ff02033c2..80d1a3a31052fe55 100644 --- a/tools/perf/util/bpf_counter.c +++ b/tools/perf/util/bpf_counter.c @@ -608,7 +608,8 @@ static int bperf__read(struct evsel *evsel) __u32 num_cpu_bpf = cpu__max_cpu(); struct bpf_perf_event_value values[num_cpu_bpf]; int reading_map_fd, err = 0; - __u32 i, j, num_cpu; + __u32 i; + int j; bperf_sync_counters(evsel); reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
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