From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Paul E. McKenney" <paulmck@linux.ibm.com>
Subject: [PATCH tip/core/rcu 1/9] torture: Don't try to offline the last CPU
Date: Tue, 26 Mar 2019 16:31:10 -0700 [thread overview]
Message-ID: <20190326233118.23057-1-paulmck@linux.ibm.com> (raw)
In-Reply-To: <20190326233054.GA21523@linux.ibm.com>
If there is only one online CPU, it doesn't make sense to try to offline
it, as any such attempt is guaranteed to fail. This commit therefore
check for this condition and refuses to attempt the nonsensical.
Reported-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Tested-By: Su Yue <suy.fnst@cn.fujitsu.com>
---
kernel/torture.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/torture.c b/kernel/torture.c
index 8faa1a9aaeb9..17b2be9bde12 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -88,6 +88,8 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
return false;
+ if (num_online_cpus() <= 1)
+ return false; /* Can't offline the last CPU. */
if (verbose > 1)
pr_alert("%s" TORTURE_FLAG
--
2.17.1
next prev parent reply other threads:[~2019-03-26 23:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-26 23:30 [PATCH tip/core/rcu 0/9] Torture-test updates for v5.2 Paul E. McKenney
2019-03-26 23:31 ` Paul E. McKenney [this message]
2019-03-26 23:31 ` [PATCH tip/core/rcu 2/9] tools/.../rcutorture: Convert to SPDX license identifier Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 3/9] rcutorture: Make rcutorture_extend_mask() comment match the code Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 4/9] rcutorture: Remove ->ext_irq_conflict field Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 5/9] rcutorture: Fix expected forward progress duration in OOM notifier Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 6/9] rcutorture: Fix cleanup path for invalid torture_type strings Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 7/9] rcuperf: Fix cleanup path for invalid perf_type strings Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 8/9] locktorture: NULL cxt.lwsa and cxt.lrsa to allow bad-arg detection Paul E. McKenney
2019-03-26 23:31 ` [PATCH tip/core/rcu 9/9] torture: Suppress false-positive CONFIG_INITRAMFS_SOURCE complaint Paul E. McKenney
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