From 8126c57f00cea3502a017b7c76df1fac58f89e88 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 10 Feb 2021 13:25:58 -0800 Subject: torture: Make jitter.sh handle large systems The current jitter.sh script expects cpumask bits to fit into whatever the awk interpreter uses for an integer, which clearly does not hold for even medium-sized systems these days. This means that on a large system, only the first 32 or 64 CPUs (depending) are subjected to jitter.sh CPU-time perturbations. This commit therefore computes a given CPU's cpumask using text manipulation rather than arithmetic shifts. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney --- tools/testing/selftests/rcutorture/bin/jitter.sh | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh index 188b864bc4bf..3a856ec2e92a 100755 --- a/tools/testing/selftests/rcutorture/bin/jitter.sh +++ b/tools/testing/selftests/rcutorture/bin/jitter.sh @@ -67,10 +67,10 @@ do srand(n + me + systime()); ncpus = split(cpus, ca); curcpu = ca[int(rand() * ncpus + 1)]; - mask = lshift(1, curcpu); - if (mask + 0 <= 0) - mask = 1; - printf("%#x\n", mask); + z = ""; + for (i = 1; 4 * i <= curcpu; i++) + z = z "0"; + print "0x" 2 ^ (curcpu % 4) z; }' < /dev/null` n=$(($n+1)) if ! taskset -p $cpumask $$ > /dev/null 2>&1 -- cgit v1.2.3-59-g8ed1b