Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#!/bin/bash
2# Check branch stack sampling
3
4# SPDX-License-Identifier: GPL-2.0
5# German Gomez <german.gomez@arm.com>, 2022
6
7shelldir=$(dirname "$0")
8# shellcheck source=lib/perf_has_symbol.sh
9. "${shelldir}"/lib/perf_has_symbol.sh
10
11# skip the test if the hardware doesn't support branch stack sampling
12# and if the architecture doesn't support filter types: any,save_type,u
13if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev/null 2>&1 ; then
14 echo "skip: system doesn't support filter types: any,save_type,u"
15 exit 2
16fi
17
18skip_test_missing_symbol brstack_bench
19
20err=0
21TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX)
22TESTPROG="perf test -w brstack"
23
24cleanup() {
25 rm -rf $TMPDIR
26 trap - EXIT TERM INT
27}
28
29trap_cleanup() {
30 set +e
31 echo "Unexpected signal in ${FUNCNAME[1]}"
32 cleanup
33 exit 1
34}
35trap trap_cleanup EXIT TERM INT
36
37test_user_branches() {
38 echo "Testing user branch stack sampling"
39
40 perf record -o "$TMPDIR/perf.data" --branch-filter any,save_type,u -- ${TESTPROG} > "$TMPDIR/record.txt" 2>&1
41 perf script -i "$TMPDIR/perf.data" --fields brstacksym > "$TMPDIR/perf.script"
42
43 # example of branch entries:
44 # brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL
45
46 expected=(
47 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$"
48 "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
49 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$"
50 "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
51 "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$"
52 "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$"
53 "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$"
54 "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND/.*$"
55 )
56 for x in "${expected[@]}"
57 do
58 if ! tr -s ' ' '\n' < "$TMPDIR/perf.script" | grep -E -m1 -q "$x"
59 then
60 echo "Branches missing $x"
61 err=1
62 fi
63 done
64 # some branch types are still not being tested:
65 # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX
66}
67
68# first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u"
69# second argument are the expected branch types for the given filter
70test_filter() {
71 test_filter_filter=$1
72 test_filter_expect=$2
73
74 echo "Testing branch stack filtering permutation ($test_filter_filter,$test_filter_expect)"
75 perf record -o "$TMPDIR/perf.data" --branch-filter "$test_filter_filter,save_type,u" -- ${TESTPROG} > "$TMPDIR/record.txt" 2>&1
76 perf script -i "$TMPDIR/perf.data" --fields brstack > "$TMPDIR/perf.script"
77
78 # fail if we find any branch type that doesn't match any of the expected ones
79 # also consider UNKNOWN branch types (-)
80 if [ ! -s "$TMPDIR/perf.script" ]
81 then
82 echo "Empty script output"
83 err=1
84 return
85 fi
86 # Look for lines not matching test_filter_expect ignoring issues caused
87 # by empty output
88 tr -s ' ' '\n' < "$TMPDIR/perf.script" | grep '.' | \
89 grep -E -vm1 "^[^ ]*/($test_filter_expect|-|( *))/.*$" \
90 > "$TMPDIR/perf.script-filtered" || true
91 if [ -s "$TMPDIR/perf.script-filtered" ]
92 then
93 echo "Unexpected branch filter in script output"
94 cat "$TMPDIR/perf.script"
95 err=1
96 return
97 fi
98}
99
100set -e
101
102test_user_branches
103
104test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ"
105test_filter "call" "CALL|SYSCALL"
106test_filter "cond" "COND"
107test_filter "any_ret" "RET|COND_RET|SYSRET|ERET"
108
109test_filter "call,cond" "CALL|SYSCALL|COND"
110test_filter "any_call,cond" "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND"
111test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET"
112
113cleanup
114exit $err