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Subject[PATCH 3/9] perf evlist: introduce open counters method
Date
Superset of the open counters code in perf-top and perf-record -
combining retry handling and error handling. Should be functionally
equivalent.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
tools/perf/util/evlist.c | 127 +++++++++++++++++++++++++++++++++++++++++++++-
tools/perf/util/evlist.h | 3 ++
2 files changed, 129 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index a41dc4a..bce2f58 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -15,7 +15,7 @@
#include "evlist.h"
#include "evsel.h"
#include <unistd.h>
-
+#include "debug.h"
#include "parse-events.h"

#include <sys/mman.h>
@@ -838,3 +838,128 @@ size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)

return printed + fprintf(fp, "\n");;
}
+
+int perf_evlist__open_counters(struct perf_evlist *evlist,
+ struct perf_record_opts *opts)
+{
+ struct perf_evsel *pos;
+ int rc = 0;
+
+ list_for_each_entry(pos, &evlist->entries, node) {
+ struct perf_event_attr *attr = &pos->attr;
+
+ /*
+ * Carried over from perf-record:
+ * Check if parse_single_tracepoint_event has already asked for
+ * PERF_SAMPLE_TIME.
+ *
+ * XXX this is kludgy but short term fix for problems introduced by
+ * eac23d1c that broke 'perf script' by having different sample_types
+ * when using multiple tracepoint events when we use a perf binary
+ * that tries to use sample_id_all on an older kernel.
+ *
+ * We need to move counter creation to perf_session, support
+ * different sample_types, etc.
+ */
+ bool time_needed = attr->sample_type & PERF_SAMPLE_TIME;
+
+fallback_missing_features:
+ if (opts->exclude_guest_missing)
+ attr->exclude_guest = attr->exclude_host = 0;
+retry_sample_id:
+ attr->sample_id_all = opts->sample_id_all_missing ? 0 : 1;
+try_again:
+ if (perf_evsel__open(pos, evlist->cpus, evlist->threads) < 0) {
+ int err = errno;
+
+ if (err == EPERM || err == EACCES) {
+ ui__error_paranoid();
+ rc = -err;
+ goto out;
+ } else if (err == ENODEV && opts->target.cpu_list) {
+ pr_err("No such device - did you specify"
+ " an out-of-range profile CPU?\n");
+ rc = -err;
+ goto out;
+ } else if (err == EINVAL) {
+ if (!opts->exclude_guest_missing &&
+ (attr->exclude_guest || attr->exclude_host)) {
+ pr_debug("Old kernel, cannot exclude "
+ "guest or host samples.\n");
+ opts->exclude_guest_missing = true;
+ goto fallback_missing_features;
+ } else if (!opts->sample_id_all_missing) {
+ /*
+ * Old kernel, no attr->sample_id_type_all field
+ */
+ opts->sample_id_all_missing = true;
+ if (!opts->sample_time &&
+ !opts->raw_samples &&
+ !time_needed)
+ attr->sample_type &= ~PERF_SAMPLE_TIME;
+ goto retry_sample_id;
+ }
+ }
+
+ /*
+ * If it's cycles then fall back to hrtimer
+ * based cpu-clock-tick sw counter, which
+ * is always available even if no PMU support:
+ *
+ * PPC returns ENXIO until 2.6.37 (behavior changed
+ * with commit b0a873e).
+ */
+ if ((err == ENOENT || err == ENXIO) &&
+ (attr->type == PERF_TYPE_HARDWARE) &&
+ (attr->config == PERF_COUNT_HW_CPU_CYCLES)) {
+
+ if (verbose)
+ ui__warning("Cycles event not supported,\n"
+ "trying to fall back to cpu-clock-ticks\n");
+
+ attr->type = PERF_TYPE_SOFTWARE;
+ attr->config = PERF_COUNT_SW_CPU_CLOCK;
+ if (pos->name) {
+ free(pos->name);
+ pos->name = NULL;
+ }
+ goto try_again;
+ }
+
+ if (err == ENOENT) {
+ ui__error("The %s event is not supported.\n",
+ perf_evsel__name(pos));
+ rc = -err;
+ goto out;
+ } else if (err == EMFILE) {
+ ui__error("Too many events are opened.\n"
+ "Try again after reducing the number of events\n");
+ rc = -err;
+ goto out;
+ }
+
+ ui__error("sys_perf_event_open() syscall returned with "
+ "%d (%s) for event %s. /bin/dmesg may provide"
+ "additional information.\n",
+ err, strerror(err), perf_evsel__name(pos));
+
+#if defined(__i386__) || defined(__x86_64__)
+ if ((attr->type == PERF_TYPE_HARDWARE) &&
+ (err == EOPNOTSUPP)) {
+ pr_err("No hardware sampling interrupt available."
+ " No APIC? If so then you can boot the kernel"
+ " with the \"lapic\" boot parameter to"
+ " force-enable it.\n");
+ rc = -err;
+ goto out;
+ }
+#endif
+
+ pr_err("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
+ rc = -err;
+ goto out;
+ }
+ }
+out:
+ return rc;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 56003f7..270e546 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -135,4 +135,7 @@ static inline struct perf_evsel *perf_evlist__last(struct perf_evlist *evlist)
}

size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp);
+
+int perf_evlist__open_counters(struct perf_evlist *evlist,
+ struct perf_record_opts *opts);
#endif /* __PERF_EVLIST_H */
--
1.7.10.1


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