tools/perf/tests/shell/test_brstack.sh

Source file repositories/reference/linux-study-clean/tools/perf/tests/shell/test_brstack.sh

File Facts

System
Linux kernel
Corpus path
tools/perf/tests/shell/test_brstack.sh
Extension
.sh
Size
7326 bytes
Lines
249
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#!/bin/bash
# Check branch stack sampling

# SPDX-License-Identifier: GPL-2.0
# German Gomez <german.gomez@arm.com>, 2022

shelldir=$(dirname "$0")
# shellcheck source=lib/perf_has_symbol.sh
. "${shelldir}"/lib/perf_has_symbol.sh

# skip the test if the hardware doesn't support branch stack sampling
# and if the architecture doesn't support filter types: any,save_type,u
if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev/null 2>&1 ; then
	echo "skip: system doesn't support filter types: any,save_type,u"
	exit 2
fi

skip_test_missing_symbol brstack_bench

err=0
TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX)
TESTPROG="perf test -w brstack"

cleanup() {
	rm -rf $TMPDIR
	trap - EXIT TERM INT
}

trap_cleanup() {
	set +e
	echo "Unexpected signal in ${FUNCNAME[1]}"
	cleanup
	exit 1
}
trap trap_cleanup EXIT TERM INT

is_arm64() {
	[ "$(uname -m)" = "aarch64" ];
}

has_kaslr_bug() {
	[ "$(uname -m)" != "aarch64" ];
}

check_branches() {
	if ! tr -s ' ' '\n' < "$TMPDIR/perf.script" | grep -E -m1 -q "$1"; then
		echo "ERROR: Branches missing $1"
		err=1
	fi
}

test_user_branches() {
	echo "Testing user branch stack sampling"

	start_err=$err
	err=0
	perf record -o "$TMPDIR/perf.data" --branch-filter any,save_type,u -- ${TESTPROG} > "$TMPDIR/record.txt" 2>&1
	perf script -i "$TMPDIR/perf.data" --fields brstacksym > "$TMPDIR/perf.script"

	# example of branch entries:
	# 	brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL

	expected=(
		"^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$"
		"^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
		"^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$"
		"^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$"
		"^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$"
		"^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$"
		"^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$"

Annotation

Implementation Notes