linux-kernel - [PATCH tip/core/rcu 4/4] locktorture: Forgive apparent unfairness if CPU hotplug

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Message-Id: <20200215000337.14667-4-paulmck@kernel.org>
Date:   Fri, 14 Feb 2020 16:03:37 -0800
From:   paulmck@...nel.org
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel-team@...com, mingo@...nel.org,
        jiangshanlai@...il.com, dipankar@...ibm.com,
        akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
        josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
        rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
        fweisbec@...il.com, oleg@...hat.com, joel@...lfernandes.org,
        "Paul E. McKenney" <paulmck@...nel.org>
Subject: [PATCH tip/core/rcu 4/4] locktorture: Forgive apparent unfairness if CPU hotplug

From: "Paul E. McKenney" <paulmck@...nel.org>

If CPU hotplug testing is enabled, a lock might appear to be maximally
unfair just because one of the CPUs was offline almost all the time.
This commit therefore forgives unfairness if CPU hotplug testing was
enabled.

Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
 kernel/locking/locktorture.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 5baf904..5efbfc6 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -704,7 +704,8 @@ static void __torture_print_stats(char *page,
 	page += sprintf(page,
 			"%s:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",
 			write ? "Writes" : "Reads ",
-			sum, max, min, max / 2 > min ? "???" : "",
+			sum, max, min,
+			!onoff_interval && max / 2 > min ? "???" : "",
 			fail, fail ? "!!!" : "");
 	if (fail)
 		atomic_inc(&cxt.n_lock_torture_errors);
-- 
2.9.5