Messages in this thread Patch in this message | | | Subject | Re: [RFC PATCH v1 25/37] perf evsel: move event open in evsel__open_cpu to separate function | From | Riccardo Mancini <> | Date | Fri, 03 Sep 2021 23:52:18 +0200 |
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Hi Arnaldo,
thanks for your review and your suggestions, and also for the PRIu64 patch.
On Tue, 2021-08-31 at 16:54 -0300, Arnaldo Carvalho de Melo wrote: > Em Sat, Aug 21, 2021 at 11:19:31AM +0200, Riccardo Mancini escreveu: > > This is the final patch splitting evsel__open_cpu. > > This patch moves the entire loop code to a separate function, to be > > reused for the multithreaded code. > > Are you going to use that 'enum perf_event_open_err' somewhere else? > I.e. is there a need to expose it in evsel.h?
Yes, in the next patch (26/37). It's being used to expose a function that just does the perf_event_open calls for an evsel. It needs to return such structure to provide information about the error (which return code, at which thread).
> > I'm stopping at this patch to give the ones I merged so far some > testing, will now push it to tmp.perf/core.
I checked tmp.perf/core and it looks good to me. I also did some additional tests to check that fallback mechanisms where working:
check missing pid being ignored (rerun until warning is shown) $ sudo ./perf bench internals evlist-open-close -i10 -u $UID
check that weak group fallback is working $ sudo ./perf record -e '{cycles,cache-misses,cache- references,cpu_clk_unhalted.thread,cycles,cycles,cycles}:W'
check that precision_ip fallback is working: edited perf-sys.h to make sys_perf_event_open fail if precision_ip > 2 $ sudo ./perf record -e '{cycles,cs}:P'
I've also run perf-test on my machine and it's passing too. I'm encounteirng one fail on the "BPF filter" test (42), which is present also in perf/core, so it should not be related to this patch.
Thanks, Riccardo
> > - Arnaldo > > > Signed-off-by: Riccardo Mancini <rickyman7@gmail.com> > > --- > > tools/perf/util/evsel.c | 142 ++++++++++++++++++++++++---------------- > > tools/perf/util/evsel.h | 12 ++++ > > 2 files changed, 99 insertions(+), 55 deletions(-) > > > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > > index 2e95416b8320c6b9..e41f55a7a70ea630 100644 > > --- a/tools/perf/util/evsel.c > > +++ b/tools/perf/util/evsel.c > > @@ -1945,6 +1945,82 @@ bool evsel__increase_rlimit(enum rlimit_action > > *set_rlimit) > > return false; > > } > > > > +static struct perf_event_open_result perf_event_open(struct evsel *evsel, > > + pid_t pid, int cpu, int thread, > > + struct perf_cpu_map *cpus, > > + struct perf_thread_map *threads) > > +{ > > + int fd, group_fd, rc; > > + struct perf_event_open_result res; > > + > > + if (!evsel->cgrp && !evsel->core.system_wide) > > + pid = perf_thread_map__pid(threads, thread); > > + > > + group_fd = get_group_fd(evsel, cpu, thread); > > + > > + test_attr__ready(); > > + > > + pr_debug2_peo("sys_perf_event_open: pid %d cpu %d group_fd %d flags > > %#lx", > > + pid, cpus->map[cpu], group_fd, evsel->open_flags); > > + > > + fd = sys_perf_event_open(&evsel->core.attr, pid, cpus->map[cpu], > > + group_fd, evsel->open_flags); > > + > > + FD(evsel, cpu, thread) = fd; > > + res.fd = fd; > > + > > + if (fd < 0) { > > + rc = -errno; > > + > > + pr_debug2_peo("\nsys_perf_event_open failed, error %d\n", > > + rc); > > + res.rc = rc; > > + res.err = PEO_FALLBACK; > > + return res; > > + } > > + > > + bpf_counter__install_pe(evsel, cpu, fd); > > + > > + if (unlikely(test_attr__enabled)) { > > + test_attr__open(&evsel->core.attr, pid, > > + cpus->map[cpu], fd, > > + group_fd, evsel->open_flags); > > + } > > + > > + pr_debug2_peo(" = %d\n", fd); > > + > > + if (evsel->bpf_fd >= 0) { > > + int evt_fd = fd; > > + int bpf_fd = evsel->bpf_fd; > > + > > + rc = ioctl(evt_fd, > > + PERF_EVENT_IOC_SET_BPF, > > + bpf_fd); > > + if (rc && errno != EEXIST) { > > + pr_err("failed to attach bpf fd %d: %s\n", > > + bpf_fd, strerror(errno)); > > + res.rc = -EINVAL; > > + res.err = PEO_ERROR; > > + return res; > > + } > > + } > > + > > + /* > > + * If we succeeded but had to kill clockid, fail and > > + * have evsel__open_strerror() print us a nice error. > > + */ > > + if (perf_missing_features.clockid || > > + perf_missing_features.clockid_wrong) { > > + res.rc = -EINVAL; > > + res.err = PEO_ERROR; > > + return res; > > + } > > + > > + res.rc = 0; > > + res.err = PEO_SUCCESS; > > + return res; > > +} > > + > > static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, > > struct perf_thread_map *threads, > > int start_cpu, int end_cpu) > > @@ -1952,6 +2028,7 @@ static int evsel__open_cpu(struct evsel *evsel, struct > > perf_cpu_map *cpus, > > int cpu, thread, nthreads; > > int pid = -1, err, old_errno; > > enum rlimit_action set_rlimit = NO_CHANGE; > > + struct perf_event_open_result peo_res; > > > > err = __evsel__prepare_open(evsel, cpus, threads); > > if (err) > > @@ -1979,67 +2056,22 @@ static int evsel__open_cpu(struct evsel *evsel, struct > > perf_cpu_map *cpus, > > for (cpu = start_cpu; cpu < end_cpu; cpu++) { > > > > for (thread = 0; thread < nthreads; thread++) { > > - int fd, group_fd; > > retry_open: > > if (thread >= nthreads) > > break; > > > > - if (!evsel->cgrp && !evsel->core.system_wide) > > - pid = perf_thread_map__pid(threads, thread); > > - > > - group_fd = get_group_fd(evsel, cpu, thread); > > - > > - test_attr__ready(); > > - > > - pr_debug2_peo("sys_perf_event_open: pid %d cpu %d > > group_fd %d flags %#lx", > > - pid, cpus->map[cpu], group_fd, evsel- > > >open_flags); > > + peo_res = perf_event_open(evsel, pid, cpu, thread, > > cpus, > > + threads); > > > > - fd = sys_perf_event_open(&evsel->core.attr, pid, cpus- > > >map[cpu], > > - group_fd, evsel->open_flags); > > - > > - FD(evsel, cpu, thread) = fd; > > - > > - if (fd < 0) { > > - err = -errno; > > - > > - pr_debug2_peo("\nsys_perf_event_open failed, > > error %d\n", > > - err); > > + err = peo_res.rc; > > + switch (peo_res.err) { > > + case PEO_SUCCESS: > > + set_rlimit = NO_CHANGE; > > + continue; > > + case PEO_FALLBACK: > > goto try_fallback; > > - } > > - > > - bpf_counter__install_pe(evsel, cpu, fd); > > - > > - if (unlikely(test_attr__enabled)) { > > - test_attr__open(&evsel->core.attr, pid, cpus- > > >map[cpu], > > - fd, group_fd, evsel- > > >open_flags); > > - } > > - > > - pr_debug2_peo(" = %d\n", fd); > > - > > - if (evsel->bpf_fd >= 0) { > > - int evt_fd = fd; > > - int bpf_fd = evsel->bpf_fd; > > - > > - err = ioctl(evt_fd, > > - PERF_EVENT_IOC_SET_BPF, > > - bpf_fd); > > - if (err && errno != EEXIST) { > > - pr_err("failed to attach bpf fd %d: > > %s\n", > > - bpf_fd, strerror(errno)); > > - err = -EINVAL; > > - goto out_close; > > - } > > - } > > - > > - set_rlimit = NO_CHANGE; > > - > > - /* > > - * If we succeeded but had to kill clockid, fail and > > - * have evsel__open_strerror() print us a nice error. > > - */ > > - if (perf_missing_features.clockid || > > - perf_missing_features.clockid_wrong) { > > - err = -EINVAL; > > + default: > > + case PEO_ERROR: > > goto out_close; > > } > > } > > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h > > index 0a245afab2d87d74..8c9827a93ac001a7 100644 > > --- a/tools/perf/util/evsel.h > > +++ b/tools/perf/util/evsel.h > > @@ -282,6 +282,18 @@ int evsel__enable(struct evsel *evsel); > > int evsel__disable(struct evsel *evsel); > > int evsel__disable_cpu(struct evsel *evsel, int cpu); > > > > +enum perf_event_open_err { > > + PEO_SUCCESS, > > + PEO_FALLBACK, > > + PEO_ERROR > > +}; > > + > > +struct perf_event_open_result { > > + enum perf_event_open_err err; > > + int rc; > > + int fd; > > +}; > > + > > int evsel__open_per_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, int > > cpu); > > int evsel__open_per_thread(struct evsel *evsel, struct perf_thread_map > > *threads); > > int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus, > > -- > > 2.31.1 >
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