1 files changed, 54 insertions, 0 deletions
diff --git a/src/seastar/scripts/seastar-cpu-map.sh b/src/seastar/scripts/seastar-cpu-map.sh
new file mode 100755
index 000000000..e6cc41efa
--- /dev/null
+++ b/src/seastar/scripts/seastar-cpu-map.sh
@@ -0,0 +1,54 @@
+#!/bin/bash
+# !
+# ! Usage: ./seastar-cpu-map.sh -p <process_PID> -n <process_Name> -s (optional) <shard>
+# !
+# ! List CPU affinity for a particular running process
+# !  providing a map of threads -> shard, for any seastar apps.
+# ! Ex.: ./seastar-cpu-map.sh -n scylla
+# !      ./seastar-cpu-map.sh -n scylla -s 0
+# !      ./seastar-cpu-map.sh -p 34
+# !      ./seastar-cpu-map.sh -p 32 -s 12
+
+usage() {
+    cat $0 | grep ^"# !" | cut -d"!" -f2-
+}
+
+while getopts 'p:n:s:' option; do
+  case "$option" in
+    p) PID=$OPTARG
+        ;;
+    n) PID=`pgrep --newest --exact $OPTARG`
+        ;;
+    s) SHARD=$OPTARG
+        ;;
+    :) printf "missing argument for -%s\n" "$OPTARG" >&2
+       usage >&2
+       exit 1
+       ;;
+    \?) printf "illegal option: -%s\n" "$OPTARG" >&2
+       usage >&2
+       exit 1
+       ;;
+  esac
+done
+
+if [ $# -eq 0 ]; then usage >&2; exit 1; fi
+
+if [ -e "/proc/$PID/task" ]; then
+  # get list of threads for given PID
+  THREADS=`ls /proc/$PID/task`
+  for i in $THREADS; do
+    # get shards from threads
+    # there were three options here to get the shard number:
+    # reactor-xx, syscall-xx and timer-xx
+    # syscall was preferred because reactor as a special case (reactor-0 is called scylla)
+    SYSCALL=`grep syscall /proc/$i/comm | cut -d"-" -f2`
+    if [ -n "$SYSCALL" ] && [ "$SYSCALL" = "$SHARD" ]; then
+      echo -e "shard: $SYSCALL, cpu:$(taskset -c -p $i | cut -d":" -f2)"
+    elif [ -n "$SYSCALL" ] && [ -z "$SHARD" ]; then
+      echo -e "shard: $SYSCALL, cpu:$(taskset -c -p $i | cut -d":" -f2)"
+    fi
+  done
+else
+  echo "Process does not exist"
+fi