perf test: Fix perf test case 84 on s390

Perf test case 84 'perf pipe recording and injection test'
sometime fails on s390, especially on z/VM virtual machines.

This is caused by a very short run time of workload

  # perf test -w noploop

which runs for 1 second. Occasionally this is not long
enough and the perf report has no samples for symbol noploop.

Fix this and enlarge the runtime for the perf work load
to 3 seconds. This ensures the symbol noploop is always
present. Since only s390 is affected, make this loop
architecture dependend.

Output before:
 Inject -b build-ids test
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.277 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.160 MB
			 /tmp/perf.data.ELzRdq (4031 samples) ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 Inject -b build-ids test [Success]

 Inject --buildid-all build-ids test
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.195 MB - ]
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.014 MB - ]
 Inject --buildid-all build-ids test [Failed - cannot find
				noploop function in pipe #2]

Output after:
Successful execution for over 10 times in a loop.

Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Suggested-by: Namhyung Kim <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

tools/perf/tests/shell/pipe_test.sh

@@ -13,6 +13,7 @@ skip_test_missing_symbol ${sym}
 data=$(mktemp /tmp/perf.data.XXXXXX)
 data2=$(mktemp /tmp/perf.data2.XXXXXX)
 prog="perf test -w noploop"
+[ "$(uname -m)" = "s390x" ] && prog="$prog 3"
 err=0
 
 set -e