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From: Yunfeng Ye <yeyunfeng@huawei.com>
To: <williams@redhat.com>, <jkacur@redhat.com>
Cc: <linux-rt-users@vger.kernel.org>,
	Shiyuan Hu <hushiyuan@huawei.com>,
	Hewenliang <hewenliang4@huawei.com>
Subject: [PATCH] rt-tests: cyclictest: try not to share the same cpu with main thread
Date: Sat, 20 Jun 2020 09:48:07 +0800
Message-ID: <60c13be0-76ad-5d95-f8d5-124cb13d0561@huawei.com> (raw)

The main thread will interfere with the test thread and try not to share
the same CPU with the main thread when the number of thread is less than
max_cpus.

Signed-off-by: yeyunfeng <yeyunfeng@huawei.com>
---
 src/cyclictest/cyclictest.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 989113fb3483..b3d72caa10ce 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -1080,7 +1080,8 @@ static int cpu_for_thread_sp(int thread_num, int max_cpus)
 		fatal("No allowable cpus to run on\n");
 	}

-	m = thread_num % num_cpus;
+	/* just don't try to share the same cpu with main thread */
+	m = (thread_num + 1) % num_cpus;

 	/* there are num_cpus bits set, we want position of m'th one */
 	for (i = 0, cpu = 0; i < max_cpus; i++) {
-- 
1.8.3.1


             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-20  1:48 Yunfeng Ye [this message]
2020-07-01 16:24 ` John Kacur
2020-07-02  1:45   ` Yunfeng Ye

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