[tip:core/rseq] rseq/selftests: Adapt number of threads to the number of detected CPUs

[tip-bot for Mathieu Desnoyers]

Commit-ID:  03a33ecc26af28ca9535de2b0612c54deafa9728
Gitweb:     https://git.kernel.org/tip/03a33ecc26af28ca9535de2b0612c54deafa9728
Author:     Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
AuthorDate: Tue, 5 Mar 2019 14:47:55 -0500
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 19 Apr 2019 12:42:14 +0200

rseq/selftests: Adapt number of threads to the number of detected CPUs

On smaller systems, running a test with 200 threads can take a long
time on machines with smaller number of CPUs.

Detect the number of online CPUs at test runtime, and multiply that
by 6 to have 6 rseq threads per CPU preempting each other.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Ben Maurer <bmaurer@xxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Chris Lameter <cl@xxxxxxxxx>
Cc: Dave Watson <davejwatson@xxxxxx>
Cc: Joel Fernandes <joelaf@xxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: linux-api@xxxxxxxxxxxxxxx
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190305194755.2602-4-mathieu.desnoyers@xxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 tools/testing/selftests/rseq/run_param_test.sh | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rseq/run_param_test.sh b/tools/testing/selftests/rseq/run_param_test.sh
index 3acd6d75ff9f..e426304fd4a0 100755
--- a/tools/testing/selftests/rseq/run_param_test.sh
+++ b/tools/testing/selftests/rseq/run_param_test.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0+ or MIT
 
+NR_CPUS=`grep '^processor' /proc/cpuinfo | wc -l`
+
 EXTRA_ARGS=${@}
 
 OLDIFS="$IFS"
@@ -28,15 +30,16 @@ IFS="$OLDIFS"
 
 REPS=1000
 SLOW_REPS=100
+NR_THREADS=$((6*${NR_CPUS}))
 
 function do_tests()
 {
 	local i=0
 	while [ "$i" -lt "${#TEST_LIST[@]}" ]; do
 		echo "Running test ${TEST_NAME[$i]}"
-		./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
+		./param_test ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
 		echo "Running compare-twice test ${TEST_NAME[$i]}"
-		./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
+		./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
 		let "i++"
 	done
 }