tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#!/bin/bash
2# perf record LBR tests (exclusive)
3# SPDX-License-Identifier: GPL-2.0
4
5set -e
6
7if [ ! -f /sys/devices/cpu/caps/branches ] && [ ! -f /sys/devices/cpu_core/caps/branches ]
8then
9 echo "Skip: only x86 CPUs support LBR"
10 exit 2
11fi
12
13err=0
14perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
15
16cleanup() {
17 rm -rf "${perfdata}"
18 rm -rf "${perfdata}".old
19 rm -rf "${perfdata}".txt
20
21 trap - EXIT TERM INT
22}
23
24trap_cleanup() {
25 cleanup
26 exit 1
27}
28trap trap_cleanup EXIT TERM INT
29
30
31lbr_callgraph_test() {
32 test="LBR callgraph"
33
34 echo "$test"
35 if ! perf record -e cycles --call-graph lbr -o "${perfdata}" perf test -w thloop
36 then
37 echo "$test [Failed support missing]"
38 if [ $err -eq 0 ]
39 then
40 err=2
41 fi
42 return
43 fi
44
45 if ! perf report --stitch-lbr -i "${perfdata}" > "${perfdata}".txt
46 then
47 cat "${perfdata}".txt
48 echo "$test [Failed in perf report]"
49 err=1
50 return
51 fi
52
53 echo "$test [Success]"
54}
55
56lbr_test() {
57 local branch_flags=$1
58 local test="LBR $2 test"
59 local threshold=$3
60 local out
61 local sam_nr
62 local bs_nr
63 local zero_nr
64 local r
65
66 echo "$test"
67 if ! perf record -e cycles $branch_flags -o "${perfdata}" perf test -w thloop
68 then
69 echo "$test [Failed support missing]"
70 perf record -e cycles $branch_flags -o "${perfdata}" perf test -w thloop || true
71 if [ $err -eq 0 ]
72 then
73 err=2
74 fi
75 return
76 fi
77
78 out=$(perf report -D -i "${perfdata}" 2> /dev/null | grep -A1 'PERF_RECORD_SAMPLE')
79 sam_nr=$(echo "$out" | grep -c 'PERF_RECORD_SAMPLE' || true)
80 if [ $sam_nr -eq 0 ]
81 then
82 echo "$test [Failed no samples captured]"
83 err=1
84 return
85 fi
86 echo "$test: $sam_nr samples"
87
88 bs_nr=$(echo "$out" | grep -c 'branch stack: nr:' || true)
89 if [ $sam_nr -ne $bs_nr ]
90 then
91 echo "$test [Failed samples missing branch stacks]"
92 err=1
93 return
94 fi
95
96 zero_nr=$(echo "$out" | grep -c 'branch stack: nr:0' || true)
97 r=$(($zero_nr * 100 / $bs_nr))
98 if [ $r -gt $threshold ]; then
99 echo "$test [Failed empty br stack ratio exceed $threshold%: $r%]"
100 err=1
101 return
102 fi
103
104 echo "$test [Success]"
105}
106
107parallel_lbr_test() {
108 err=0
109 perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
110 lbr_test "$1" "$2" "$3"
111 cleanup
112 exit $err
113}
114
115lbr_callgraph_test
116
117# Sequential
118lbr_test "-b" "any branch" 2
119lbr_test "-j any_call" "any call" 2
120lbr_test "-j any_ret" "any ret" 2
121lbr_test "-j ind_call" "any indirect call" 2
122lbr_test "-j ind_jmp" "any indirect jump" 100
123lbr_test "-j call" "direct calls" 2
124lbr_test "-j ind_call,u" "any indirect user call" 100
125lbr_test "-a -b" "system wide any branch" 2
126lbr_test "-a -j any_call" "system wide any call" 2
127
128# Parallel
129parallel_lbr_test "-b" "parallel any branch" 100 &
130pid1=$!
131parallel_lbr_test "-j any_call" "parallel any call" 100 &
132pid2=$!
133parallel_lbr_test "-j any_ret" "parallel any ret" 100 &
134pid3=$!
135parallel_lbr_test "-j ind_call" "parallel any indirect call" 100 &
136pid4=$!
137parallel_lbr_test "-j ind_jmp" "parallel any indirect jump" 100 &
138pid5=$!
139parallel_lbr_test "-j call" "parallel direct calls" 100 &
140pid6=$!
141parallel_lbr_test "-j ind_call,u" "parallel any indirect user call" 100 &
142pid7=$!
143parallel_lbr_test "-a -b" "parallel system wide any branch" 100 &
144pid8=$!
145parallel_lbr_test "-a -j any_call" "parallel system wide any call" 100 &
146pid9=$!
147
148for pid in $pid1 $pid2 $pid3 $pid4 $pid5 $pid6 $pid7 $pid8 $pid9
149do
150 set +e
151 wait $pid
152 child_err=$?
153 set -e
154 if ([ $err -eq 2 ] && [ $child_err -eq 1 ]) || [ $err -eq 0 ]
155 then
156 err=$child_err
157 fi
158done
159
160cleanup
161exit $err