[RFC PATCH v1 25/37] perf evsel: move event open in evsel__open_cpu to separate function
From: Riccardo Mancini <hidden>
Date: 2021-08-21 09:22:01
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
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. Signed-off-by: Riccardo Mancini <redacted> --- 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,
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2.31.1