perf tests: Make data symbol test wait for perf to start

The perf data symbol test waits 1 second for perf to run and collect data,
which may be too little if perf takes a long time to start up, which has
been noticed on systems with many CPUs. Use existing wait_for_perf_to_start
helper to wait for perf to start.

Signed-off-by: Adrian Hunter <[e-mail]>
Acked-by: Ian Rogers <[e-mail]>
Cc: German Gomez <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/shell/test_data_symbol.sh

···
 # SPDX-License-Identifier: GPL-2.0
 # Leo Yan <[e-mail]>, 2022
 
+shelldir=$(dirname "$0")
+# shellcheck source=lib/waiting.sh
+. "${shelldir}"/lib/waiting.sh
+
 skip_if_no_mem_event() {
 	perf mem record -e list 2>&1 | grep -E -q 'available' && return 0
 	return 2
···
 
 TEST_PROGRAM="perf test -w datasym"
 PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+ERR_FILE=$(mktemp /tmp/__perf_test.stderr.XXXXX)
 
 check_result() {
 	# The memory report format is as below:
···
 # specific CPU and test in per-CPU mode.
 is_amd=$(grep -E -c 'vendor_id.*AuthenticAMD' /proc/cpuinfo)
 if (($is_amd >= 1)); then
-	perf mem record -o ${PERF_DATA} -C 0 -- taskset -c 0 $TEST_PROGRAM &
+	perf mem record -vvv -o ${PERF_DATA} -C 0 -- taskset -c 0 $TEST_PROGRAM 2>"${ERR_FILE}" &
 else
-	perf mem record --all-user -o ${PERF_DATA} -- $TEST_PROGRAM &
+	perf mem record -vvv --all-user -o ${PERF_DATA} -- $TEST_PROGRAM 2>"${ERR_FILE}" &
 fi
 
 PERFPID=$!
+
+wait_for_perf_to_start ${PERFPID} "${ERR_FILE}"
 
 sleep 1