tools/perf/tests/shell/test_brstack.sh

   1 #!/bin/sh
   2 # Check branch stack sampling
   3
   4 # SPDX-License-Identifier: GPL-2.0
   5 # German Gomez <[email protected]>, 2022
   6
   7 # we need a C compiler to build the test programs
   8 # so bail if none is found
   9 if ! [ -x "$(command -v cc)" ]; then
  10         echo "failed: no compiler, install gcc"
  11         exit 2
  12 fi
  13
  14 # skip the test if the hardware doesn't support branch stack sampling
  15 perf record -b -o- -B true > /dev/null 2>&1 || exit 2
  16
  17 TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX)
  18
  19 cleanup() {
  20         rm -rf $TMPDIR
  21 }
  22
  23 trap cleanup exit term int
  24
  25 gen_test_program() {
  26         # generate test program
  27         cat << EOF > $1
  28 #define BENCH_RUNS 999999
  29 int cnt;
  30 void bar(void) {
  31 }                       /* return */
  32 void foo(void) {
  33         bar();          /* call */
  34 }                       /* return */
  35 void bench(void) {
  36   void (*foo_ind)(void) = foo;
  37   if ((cnt++) % 3)      /* branch (cond) */
  38     foo();              /* call */
  39   bar();                /* call */
  40   foo_ind();            /* call (ind) */
  41 }
  42 int main(void)
  43 {
  44   int cnt = 0;
  45   while (1) {
  46     if ((cnt++) > BENCH_RUNS)
  47       break;
  48     bench();            /* call */
  49   }                     /* branch (uncond) */
  50   return 0;
  51 }
  52 EOF
  53 }
  54
  55 test_user_branches() {
  56         echo "Testing user branch stack sampling"
  57
  58         gen_test_program "$TEMPDIR/program.c"
  59         cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out
  60
  61         perf record -o $TMPDIR/perf.data --branch-filter any,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1
  62         perf script -i $TMPDIR/perf.data --fields brstacksym | xargs -n1 > $TMPDIR/perf.script
  63
  64         # example of branch entries:
  65         #       foo+0x14/bar+0x40/P/-/-/0/CALL
  66
  67         set -x
  68         egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/IND_CALL$"  $TMPDIR/perf.script
  69         egrep -m1 "^foo\+[^ ]*/bar\+[^ ]*/CALL$"        $TMPDIR/perf.script
  70         egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/CALL$"      $TMPDIR/perf.script
  71         egrep -m1 "^bench\+[^ ]*/bar\+[^ ]*/CALL$"      $TMPDIR/perf.script
  72         egrep -m1 "^bar\+[^ ]*/foo\+[^ ]*/RET$"         $TMPDIR/perf.script
  73         egrep -m1 "^foo\+[^ ]*/bench\+[^ ]*/RET$"       $TMPDIR/perf.script
  74         egrep -m1 "^bench\+[^ ]*/bench\+[^ ]*/COND$"    $TMPDIR/perf.script
  75         egrep -m1 "^main\+[^ ]*/main\+[^ ]*/UNCOND$"    $TMPDIR/perf.script
  76         set +x
  77
  78         # some branch types are still not being tested:
  79         # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX
  80 }
  81
  82 # first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u"
  83 # second argument are the expected branch types for the given filter
  84 test_filter() {
  85         local filter=$1
  86         local expect=$2
  87
  88         echo "Testing branch stack filtering permutation ($filter,$expect)"
  89
  90         gen_test_program "$TEMPDIR/program.c"
  91         cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out
  92
  93         perf record -o $TMPDIR/perf.data --branch-filter $filter,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1
  94         perf script -i $TMPDIR/perf.data --fields brstack | xargs -n1 > $TMPDIR/perf.script
  95
  96         # fail if we find any branch type that doesn't match any of the expected ones
  97         # also consider UNKNOWN branch types (-)
  98         if egrep -vm1 "^[^ ]*/($expect|-|( *))$" $TMPDIR/perf.script; then
  99                 return 1
 100         fi
 101 }
 102
 103 set -e
 104
 105 test_user_branches
 106
 107 test_filter "any_call"  "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ"
 108 test_filter "call"      "CALL|SYSCALL"
 109 test_filter "cond"      "COND"
 110 test_filter "any_ret"   "RET|COND_RET|SYSRET|ERET"
 111
 112 test_filter "call,cond"         "CALL|SYSCALL|COND"
 113 test_filter "any_call,cond"             "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND"
 114 test_filter "cond,any_call,any_ret"     "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET"