tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh

   1 #!/bin/sh
   2 # SPDX-License-Identifier: GPL-2.0+
   3 #
   4 # Create an awk script that takes as input numbers of CPUs and outputs
   5 # lists of CPUs, one per line in both cases.
   6 #
   7 # Usage: kvm-get-cpus-script.sh /path/to/cpu/arrays /path/to/put/script [ /path/to/state ]
   8 #
   9 # The CPU arrays are output by kvm-assign-cpus.sh, and are valid awk
  10 # statements initializing the variables describing the system's topology.
  11 #
  12 # The optional state is input by this script (if the file exists and is
  13 # non-empty), and can also be output by this script.
  14
  15 cpuarrays="${1-/sys/devices/system/node}"
  16 scriptfile="${2}"
  17 statefile="${3}"
  18
  19 if ! test -f "$cpuarrays"
  20 then
  21         echo "File not found: $cpuarrays" 1>&2
  22         exit 1
  23 fi
  24 scriptdir="`dirname "$scriptfile"`"
  25 if ! test -d "$scriptdir" || ! test -x "$scriptdir" || ! test -w "$scriptdir"
  26 then
  27         echo "Directory not usable for script output: $scriptdir"
  28         exit 1
  29 fi
  30
  31 cat << '___EOF___' > "$scriptfile"
  32 BEGIN {
  33 ___EOF___
  34 cat "$cpuarrays" >> "$scriptfile"
  35 if test -r "$statefile"
  36 then
  37         cat "$statefile" >> "$scriptfile"
  38 fi
  39 cat << '___EOF___' >> "$scriptfile"
  40 }
  41
  42 # Do we have the system architecture to guide CPU affinity?
  43 function gotcpus()
  44 {
  45         return numnodes != "";
  46 }
  47
  48 # Return a comma-separated list of the next n CPUs.
  49 function nextcpus(n,  i, s)
  50 {
  51         for (i = 0; i < n; i++) {
  52                 if (nodecpus[curnode] == "")
  53                         curnode = 0;
  54                 if (cpu[curnode][curcpu[curnode]] == "")
  55                         curcpu[curnode] = 0;
  56                 if (s != "")
  57                         s = s ",";
  58                 s = s cpu[curnode][curcpu[curnode]];
  59                 curcpu[curnode]++;
  60                 curnode++
  61         }
  62         return s;
  63 }
  64
  65 # Dump out the current node/CPU state so that a later invocation of this
  66 # script can continue where this one left off.  Of course, this only works
  67 # when a state file was specified and where there was valid sysfs state.
  68 # Returns 1 if the state was dumped, 0 otherwise.
  69 #
  70 # Dumping the state for one system configuration and loading it into
  71 # another isn't likely to do what you want, whatever that might be.
  72 function dumpcpustate(  i, fn)
  73 {
  74 ___EOF___
  75 echo '  fn = "'"$statefile"'";' >> $scriptfile
  76 cat << '___EOF___' >> "$scriptfile"
  77         if (fn != "" && gotcpus()) {
  78                 print "curnode = " curnode ";" > fn;
  79                 for (i = 0; i < numnodes; i++)
  80                         if (curcpu[i] != "")
  81                                 print "curcpu[" i "] = " curcpu[i] ";" >> fn;
  82                 return 1;
  83         }
  84         if (fn != "")
  85                 print "# No CPU state to dump." > fn;
  86         return 0;
  87 }
  88 ___EOF___