pmdabpftrace: deduplicate tracepoint names

See bpftrace/bpftrace#1581

qa/1725

@@ -0,0 +1,38 @@
+#!/bin/sh
+# PCP QA Test No. 1725
+# Exercise the bpftrace PMDA - list tracepoints
+#
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+. ./common.bpftrace
+
+_pmdabpftrace_check
+
+status=1       # failure is the default!
+$sudo rm -rf $tmp.* $seq.full
+
+_prepare_pmda bpftrace
+trap "_pmdabpftrace_cleanup; exit \$status" 0 1 2 3 15
+_stop_auto_restart pmcd
+
+
+# real QA test starts here
+_pmdabpftrace_clean_autostart_scripts
+cat <<EOF | _pmdabpftrace_install
+# Installed by PCP QA test $seq on `date`
+EOF
+
+echo "=== check tracepoint metric ==="
+pminfo -dmtT bpftrace.info.tracepoints
+
+echo
+echo "=== check example tracepoint metric value ==="
+pminfo -f bpftrace.info.tracepoints | tr ',' '\n' \
+| grep kprobe:version_show
+
+
+_pmdabpftrace_remove
+status=0
+exit

qa/1725.out

@@ -0,0 +1,26 @@
+QA output created by 1725
+
+=== bpftrace agent installation ===
+Updating the Performance Metrics Name Space (PMNS) ...
+Terminate PMDA if already installed ...
+[...install files, make output...]
+Updating the PMCD control file, and notifying PMCD ...
+Check bpftrace metrics have appeared ... 7 metrics and X values
+
+=== check tracepoint metric ===
+
+bpftrace.info.tracepoints PMID: 151.1.2 [list all available tracepoints]
+    Data Type: string  InDom: PM_INDOM_NULL 0xffffffff
+    Semantics: instant  Units: none
+Help:
+list all available tracepoints
+
+=== check example tracepoint metric value ===
+kprobe:version_show
+
+=== remove bpftrace agent ===
+Culling the Performance Metrics Name Space ...
+bpftrace ... done
+Updating the PMCD control file, and notifying PMCD ...
+[...removing files...]
+Check bpftrace metrics have gone away ... OK

qa/group

@@ -1849,6 +1849,7 @@ x11
 1722 pmda.bpftrace local python
 1723 pmda.bpftrace local python
 1724 pmda.bpftrace local python
+1725 pmda.bpftrace local python
 1740 pmda.proc local
 1745 pmlogger libpcp pmval local
 1763 pmlogctl local

src/pmdas/bpftrace/bpftrace/utils.py

@@ -16,7 +16,10 @@ def get_bpftrace_version(bpftrace_path: str) -> Optional[Tuple]:
 
 
 def get_tracepoints_csv(bpftrace_path: str) -> str:
-    return subprocess.check_output([bpftrace_path, '-l'], encoding='utf8').strip().replace('\n', ',')
+    # use a set to prevent duplicate probes
+    # see https://github.com/iovisor/bpftrace/issues/1581
+    tracepoints = frozenset(subprocess.check_output([bpftrace_path, '-l'], encoding='utf8').split())
+    return ','.join(tracepoints)
 
 
 def asyncio_get_all_tasks(loop):