script/: add cpu-map.sh to aid manual selection of CPU cores for threads for profiling

Signed-off-by: Jose J Palacios-Perez <perezjos@uk.ibm.com>

diff --git a/src/script/cpu-map.sh b/src/script/cpu-map.sh
new file mode 100755 (executable)
index 0000000..d6fb465
--- /dev/null
+++ b/src/script/cpu-map.sh
@@ -0,0 +1,168 @@
+#!/bin/bash
+# !
+# ! Usage: ./cpu-map.sh -p <process_PIDs comma separated> -n <process_Name>
+# !                     -g <group-name:affinity-range>
+# !
+# ! Set the CPU affinity for a list of running processes
+# !
+# ! Ex.: ./cpu-map.sh -n crimson -g "alien:4-31"
+# !      ./cpu-map.sh -p ($pgrep osd) -g "rocksdb:4-7"
+# !
+# !  Important: the "affinity-range" must be a vlid argument for taskset.
+########################################################
+# Please edit the following to suit your own needs
+#
+# Regex to define the group of threads names we want to set their affinity:
+proc_group_re="alien-store-tp|rocksdb|bstore|cfin"
+# Associate array to identify the group and the thread names
+declare -A thr_grp_re_name_map=([alien]="$proc_group_re")
+# Ditto for their default affinity range:
+declare -A thr_grp_range_map=([alien]="4-7")
+# You can define further groups as needed
+
+# Range of CPU cores available: i.e. nprocs - rectors
+free_cpu_avail="8-31"
+
+# Regex of threads to ignore: do not change their affinity
+proc_ignore_re="crimson-osd|reactor|log|syscall"
+########################################################
+# Examples:
+
+# Run with 4 cores on a dual socket 8 CPucores per socket system, no hyperthreading
+#declare -A thr_grp_map=([alien-store-tp]="4-7" [rocksdb]="4-7" [bstore]="4-7" [cfin]="4-7" )
+
+########################################################
+# svcdev3 -- 56 cpus
+#declare -A thr_grp_map=([io_context_pool]="0-12" [msg-worker]="13-25" [ceph-osd]="26-38" )
+#free_cpu_avail="39-55"
+#proc_group_re="io_context_pool|msg-worker|ceph-osd"
+
+########################################################
+# sv1-cephX-- 32 cpus
+#declare -A thr_grp_map=([io_context_pool]="0-9" [msg-worker]="10-19" [ceph-osd]="20-29" )
+
+# Run with  2 cores:
+# busiest threads is msgr-worker-1, the rest of the threads segregated to the other core -- this is per OSD process
+#declare -A thr_grp_map=([msgr-worker]="0-0")
+#free_cpu_avail="1-1"
+# Regex to define the group of threads we want on its own cpu core
+#proc_group_re="msgr-worker"
+
+# Run with  4 cores:
+#declare -A thr_grp_map=([msgr-worker]="0-0" [bstore_kv]="1-1" [tp_osd_tp]="2-2")
+#free_cpu_avail="3-3"
+#proc_group_re="msgr-worker|bstore_kv|tp_osd_tp"
+
+# Run with  8 cores:
+#declare -A thr_grp_map=([msgr-worker]="0-1" [bstore_kv]="2-3" [tp_osd_tp]="4-5")
+#free_cpu_avail="6-7"
+#proc_group_re="msgr-worker|bstore_kv|tp_osd_tp"
+
+# Run with  16 cores:
+#declare -A thr_grp_map=([msgr-worker]="0-1" [bstore_kv]="2-3" [tp_osd_tp]="4-5" [rocksdb]="6-7")
+#free_cpu_avail="8-15"
+#proc_group_re="msgr-worker|bstore_kv|tp_osd_tp|rocksdb"
+
+########################################################
+
+# cores 16-31 are for FIO only
+
+usage() {
+    cat $0 | grep ^"# !" | cut -d"!" -f2-
+}
+
+# Given a thread name, find its affinity from $thr_grp_map[]
+getaffinity() {
+    local name="$1"
+    local regex="$2"
+    if [ -z "$regex" ]; then
+        echo ''
+    fi
+}
+
+# process arguments
+while getopts 'p:n:g:' option; do
+  case "$option" in
+    p) PROCESSES=$OPTARG # this should be a , separated list of pids
+        ;;
+    n) PROCESSES=$(pgrep --newest --exact $OPTARG)
+        ;;
+        # TBD. extend this argument into a map {thread_name:cpu-range}
+    g) CPUGROUP_STR=$OPTARG 
+       CPUGROUP=true
+       IFS=':' read -r -a cpu_grp_lst <<< "$CPUGROUP_STR"
+       #echo ${cpu_grp_lst[@]} #ok
+       # cpu_grp_lst[0] is the group name,
+       # cpu_grp_lst[1] is the group cpu range
+        ;;
+    :) printf "missing argument for -%s\n" "$OPTARG" >&2
+       usage >&2
+       exit 1
+       ;;
+    \?) printf "illegal option: -%s\n" "$OPTARG" >&2
+       usage >&2
+       exit 1
+       ;;
+  esac
+done
+
+if [ $# -eq 0 ]; then usage >&2; exit 1; fi
+
+declare -a other=()
+next_avail_cpu=0
+max_cpus=$(nproc)
+cpu_used=1
+j=0 # last index of the other[] array
+
+function get_affinity() {
+       local i="$1"
+}
+
+IFS=', ' read -r -a proc_list <<< "$PROCESSES"
+for PID in "${proc_list[@]}"; do
+    if [ -e "/proc/$PID/task" ]; then
+        # get list of threads for given PID
+       THREADS=$(ls /proc/$PID/task)
+       for i in $THREADS; do
+               if [ "$CPUGROUP" = true ]; then
+                       pgroup_re=${thr_grp_re_name_map[${cpu_grp_lst[0]}]}
+                       t_name=$(grep -E "$pgroup_re" /proc/$i/comm )
+                       if [ -n "$t_name" ]; then
+                               affinity=${cpu_grp_lst[1]}
+                       else
+                               # this thread is not in the group, check if we want to skip it
+                               t_name=$(grep -E "$proc_ignore_re" /proc/$i/comm )
+
+                               if [ -n "$t_name" ] && [ "$CPUGROUP" = true ]; then
+                                       echo "Skipping $i"
+                                       continue
+                               else
+                                       # so its affinity will be on the remaining cpu set
+                                       other[$(( j++ ))]="$i"
+                               fi
+                       fi
+               else
+                       # if we use them all CPUs, rotate
+                       affinity=$(( next_avail_cpu++ % max_cpus ))
+                       cpu_used=$(( cpu_used | ( 1 << $affinity )))
+                       printf "cpu_used: 0x%x\n" $cpu_used
+               fi
+               echo "$t_name: taskset -c -p $affinity $i"
+               taskset -c -p $affinity $i
+       done # threads
+    else
+        echo "Process $PID does not exist"
+    fi
+done # PID
+
+# Assign the affinity to the other threads on the remaining non-used cpus
+echo "Threads in the remaining set all with the remaining processor ids:"
+#echo "${other[@]}"
+for x in "${other[@]}"; do
+    if [ "$CPUGROUP" ]; then
+        echo taskset -c -p $free_cpu_avail $x
+    else
+        rem_affinity=$(printf "0x%x\n" $(( cpu_used ^ 0xfffffff )))
+        echo taskset -p  $rem_affinity $x
+    fi
+done