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From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     rcu@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, kernel-team@meta.com,
        rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 1/7] torture: Seed torture_random_state on CPU
Date:   Wed,  4 Jan 2023 16:44:50 -0800
Message-Id: <20230105004501.1771332-2-paulmck@kernel.org>
In-Reply-To: <20230105004454.GA1771168@paulmck-ThinkPad-P17-Gen-1>
References: <20230105004454.GA1771168@paulmck-ThinkPad-P17-Gen-1>
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The DEFINE_TORTURE_RANDOM_PERCPU() macro defines per-CPU random-number
generators for torture testing, but the seeds for each CPU's instance
will be identical if they are first used at the same time.  This commit
therefore adds the CPU number to the mix when reseeding.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/torture.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/torture.c b/kernel/torture.c
index 789aeb0e1159c..29afc62f2bfec 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -450,7 +450,7 @@ unsigned long
 torture_random(struct torture_random_state *trsp)
 {
 	if (--trsp->trs_count < 0) {
-		trsp->trs_state += (unsigned long)local_clock();
+		trsp->trs_state += (unsigned long)local_clock() + raw_smp_processor_id();
 		trsp->trs_count = TORTURE_RANDOM_REFRESH;
 	}
 	trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT +
-- 
2.31.1.189.g2e36527f23