feat(bench): harness v1.1 — PSI latency, load, device identity context [#709]

Replaces unavailable latencytop; sysstat/iotop deployed fleet-wide
separately. Redmine: https://projects.knownelement.com/issues/709

proxmox/perf/bench/bench-run.sh

@@ -30,6 +30,20 @@ b meta path "$BENCH_DIR"
 b meta runtime "$RUNTIME"
 b meta size "$SIZE"
 
+# context: load, PSI latency (pressure stall info — the latencytop
+# replacement on modern kernels), and the backing device of BENCH_DIR
+b meta load "$(cat /proc/loadavg)"
+if [ -d /proc/pressure ]; then
+    for rsc in io cpu memory; do
+        [ -r "/proc/pressure/$rsc" ] && \
+            b "psi_${rsc}_some_avg10" "$(awk '{for(i=1;i<=NF;i++) if($i ~ /^avg10=/) sub("avg10=","",$i)} /^some/ {print $2; exit}' "/proc/pressure/$rsc" 2>/dev/null)"
+    done
+fi
+DEV=$(df -P "$BENCH_DIR" | awk 'NR==2 {print $1}')
+b meta bench_device "$DEV"
+[ -r "/sys/block/$(basename "$DEV")/queue/rotational" ] && \
+    b meta bench_device_rotational "$(cat "/sys/block/$(basename "$DEV")/queue/rotational")"
+
 # fio may print human notes (e.g. sync-engine warnings) before the JSON on
 # stdout; strip everything before the opening brace so jq always gets JSON.
 parse_fio() { # $1=json-file $2=testname $3=read|write
@@ -58,6 +72,11 @@ run_fio seqwrite1m  write --filename="$BENCH_DIR/perf-test-file" --rw=write    -
 
 rm -f "$BENCH_DIR/.fio-out.json" "$BENCH_DIR/.fio-err"
 
+# post-run pressure + load (did the bench itself saturate the box?)
+b meta load_end "$(cat /proc/loadavg)"
+[ -r /proc/pressure/io ] && \
+    b psi_io_some_avg10_end "$(awk '/^some/ {for(i=1;i<=NF;i++) if($i ~ /^avg10=/) {sub("avg10=","",$i); print $i; exit}}' /proc/pressure/io)"
+
 # network: only when a server is provided
 if [ -n "${IPERF_SERVER:-}" ] && command -v iperf3 >/dev/null 2>&1; then
     NET=$(iperf3 -c "$IPERF_SERVER" -t 10 -P 4 -J 2>/dev/null | jq -r '.end.sum_received.bits_per_second' 2>/dev/null)