[tip: perf/core] perf tests: Fixes hang in zstd compression test by changing the source of random data

[tip-bot2 for James Clark]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     d93fc7ac88c7347d1c31ca158d1466d1ce2097e1
Gitweb:        https://git.kernel.org/tip/d93fc7ac88c7347d1c31ca158d1466d1ce2097e1
Author:        James Clark <James.Clark@xxxxxxx>
AuthorDate:    Thu, 22 Aug 2019 13:55:15 
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Mon, 26 Aug 2019 11:58:29 -03:00

perf tests: Fixes hang in zstd compression test by changing the source of random data

Running 'perf test' with zstd compression linked will hang at the test
'Zstd perf.data compression/decompression' because /dev/random blocks
reads until there is enough entropy. This means that the test will
appear to never complete unless the mouse is continually moved while
running it.

Signed-off-by: James Clark <james.clark@xxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
Cc: Jeremy Linton <jeremy.linton@xxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/3d8cc701-df4e-f949-1715-5118b530e990@xxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/tests/shell/record+zstd_comp_decomp.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/record+zstd_comp_decomp.sh b/tools/perf/tests/shell/record+zstd_comp_decomp.sh
index 899604d..63a91ec 100755
--- a/tools/perf/tests/shell/record+zstd_comp_decomp.sh
+++ b/tools/perf/tests/shell/record+zstd_comp_decomp.sh
@@ -13,7 +13,7 @@ skip_if_no_z_record() {
 collect_z_record() {
 	echo "Collecting compressed record file:"
 	$perf_tool record -o $trace_file -g -z -F 5000 -- \
-		dd count=500 if=/dev/random of=/dev/null
+		dd count=500 if=/dev/urandom of=/dev/null
 }
 
 check_compressed_stats() {