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From: Josh Triplett <josh@joshtriplett.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
	laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
	niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, Valdis.Kletnieks@vt.edu,
	dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com,
	fweisbec@gmail.com, patches@linaro.org,
	"Paul E. McKenney" <paul.mckenney@linaro.org>,
	Julia Lawall <julia@diku.dk>
Subject: Re: [PATCH RFC tip/core/rcu 31/41] rcu: Add CPU-stall capability to rcutorture
Date: Wed, 1 Feb 2012 21:53:11 -0800	[thread overview]
Message-ID: <20120202055310.GR29058@leaf> (raw)
In-Reply-To: <1328125319-5205-31-git-send-email-paulmck@linux.vnet.ibm.com>

On Wed, Feb 01, 2012 at 11:41:49AM -0800, Paul E. McKenney wrote:
> --- a/kernel/rcutorture.c
> +++ b/kernel/rcutorture.c
> +/* Spawn CPU-stall kthread, if stall_cpu specified. */
> +static int __init rcu_torture_stall_init(void)
> +{
> +	if (stall_cpu <= 0)
> +		return 0;
> +	stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall");
> +	if (IS_ERR(stall_task)) {
> +		stall_task = NULL;
> +		return PTR_ERR(stall_task);

This seems...unlikely to produce the desired result. :)

A quick check turns up the same bug in rcutorture_onoff_init.

This suggests a possible Coccinelle check, for uses of PTR_ERR(foo) after
foo = (any constant other than ERR_PTR(foo)).

- Josh Triplett

  reply	other threads:[~2012-02-02  5:53 UTC|newest]

Thread overview: 104+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-01 19:41 [PATCH RFC 0/41] RCU commits for 3.4 Paul E. McKenney
2012-02-01 19:41 ` [PATCH RFC tip/core/rcu 01/41] rcu: Bring RTFP.txt up to date Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 02/41] rcu: Improve synchronize_rcu() diagnostics Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 03/41] rcu: Add lockdep-RCU checks for simple self-deadlock Paul E. McKenney
2012-02-02  0:55     ` Josh Triplett
2012-02-02 16:20       ` Paul E. McKenney
2012-02-02 19:56         ` Josh Triplett
2012-02-02 20:42           ` Paul E. McKenney
2012-02-03  9:04             ` Josh Triplett
2012-02-03 18:05               ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 04/41] rcu: Add diagnostic for misaligned rcu_head structures Paul E. McKenney
2012-02-02  1:00     ` Josh Triplett
2012-02-02 16:22       ` Paul E. McKenney
2012-02-02 20:11         ` Josh Triplett
2012-02-02  1:01     ` Josh Triplett
2012-02-02 16:27       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 05/41] rcu: Avoid waking up CPUs having only kfree_rcu() callbacks Paul E. McKenney
2012-02-02  1:15     ` Josh Triplett
2012-02-02 16:34       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 06/41] rcu: Move RCU_TRACE to lib/Kconfig.debug Paul E. McKenney
2012-02-02  1:39     ` Josh Triplett
2012-02-02 17:05       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 07/41] s390: Convert call_rcu() to kfree_rcu() Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 08/41] tcm_fc: " Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 09/41] ipv4: " Paul E. McKenney
2012-02-01 19:49     ` David Miller
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 10/41] " Paul E. McKenney
2012-02-01 19:50     ` David Miller
2012-02-02  0:24     ` Josh Triplett
2012-02-02 15:56       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 11/41] mac80211: " Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 12/41] rcu: Simplify offline processing Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 13/41] rcu: Make rcutorture flag online/offline failures Paul E. McKenney
2012-02-02  1:46     ` Josh Triplett
2012-02-02 17:08       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 14/41] rcu: Limit lazy-callback duration Paul E. McKenney
2012-02-02  2:03     ` Josh Triplett
2012-02-02 17:13       ` Paul E. McKenney
2012-02-03  4:07         ` Josh Triplett
2012-02-03  5:54           ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 15/41] rcu: Check for callback invocation from offline CPUs Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 16/41] rcu: Don't make callbacks go through second full grace period Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 17/41] rcu: Remove single-rcu_node optimization in rcu_start_gp() Paul E. McKenney
2012-02-02  2:13     ` Josh Triplett
2012-02-02 17:16       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 18/41] rcu: Protect __rcu_read_unlock() against scheduler-using irq handlers Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 19/41] rcu: Streamline code produced by __rcu_read_unlock() Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 20/41] rcu: Prevent RCU callbacks from executing before scheduler initialized Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 21/41] rcu: Inform RCU of irq_exit() activity Paul E. McKenney
2012-02-02  2:30     ` Josh Triplett
2012-02-02 17:30       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 22/41] rcu: Simplify unboosting checks Paul E. McKenney
2012-02-02  2:38     ` Josh Triplett
2012-02-02 17:48       ` Paul E. McKenney
2012-02-03  4:23         ` Josh Triplett
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 23/41] rcu: Clean up straggling rcu_preempt_needs_cpu() name Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 24/41] rcu: Check for idle-loop entry while in RCU read-side critical section Paul E. McKenney
2012-02-02  5:13     ` Josh Triplett
2012-02-02 17:50       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 25/41] rcu: Make rcu_sleep_check() also check rcu_lock_map Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 26/41] rcu: Note that rcu_access_pointer() can be used for teardown Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 27/41] rcu: Remove #ifdef CONFIG_SMP from TREE_RCU Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 28/41] rcu: Set RCU CPU stall times via sysfs Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 29/41] rcu: Print scheduling-clock information on RCU CPU stall-warning messages Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 30/41] rcutorture: Permit holding off CPU-hotplug operations during boot Paul E. McKenney
2012-02-02  5:43     ` Josh Triplett
2012-02-02 17:56       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 31/41] rcu: Add CPU-stall capability to rcutorture Paul E. McKenney
2012-02-02  5:53     ` Josh Triplett [this message]
2012-02-02  9:15       ` Julia Lawall
2012-02-02 18:03         ` Paul E. McKenney
2012-02-02 18:00       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 32/41] rcu: Update stall-warning documentation Paul E. McKenney
2012-02-02  5:56     ` Josh Triplett
2012-02-02 18:18       ` Paul E. McKenney
2012-02-03  5:42         ` Josh Triplett
2012-02-03  5:58           ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 33/41] rcu: Make boolean rcutorture parameters be of type "bool" Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 34/41] rcu: Check for illegal use of RCU from offlined CPUs Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 35/41] rcu: Move synchronize_sched_expedited() to rcutree.c Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 36/41] rcu: No interrupt disabling for rcu_prepare_for_idle() Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 37/41] lockdep: Add CPU-idle/offline warning to lockdep-RCU splat Paul E. McKenney
2012-02-02  6:07     ` Josh Triplett
2012-02-02 18:30       ` Paul E. McKenney
2012-02-03  6:12         ` Josh Triplett
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 38/41] rcu: Rework detection of use of RCU by offline CPUs Paul E. McKenney
2012-02-02  6:11     ` Josh Triplett
2012-02-02 18:31       ` Paul E. McKenney
2012-02-03  9:17         ` Josh Triplett
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 39/41] rcu: Wait at least a jiffy before declaring a CPU to be offline Paul E. McKenney
2012-02-02  6:12     ` Josh Triplett
2012-02-02 18:27       ` Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 40/41] rcu: Call out dangers of expedited RCU primitives Paul E. McKenney
2012-02-01 19:41   ` [PATCH RFC tip/core/rcu 41/41] rcu: Trace only after NULL-pointer check Paul E. McKenney
2012-02-02  0:18   ` [PATCH RFC tip/core/rcu 01/41] rcu: Bring RTFP.txt up to date Josh Triplett
2012-02-02  1:33     ` Paul E. McKenney
2012-02-02  2:01       ` Josh Triplett
2012-02-02 16:47         ` Paul E. McKenney
2012-02-02 22:32           ` Josh Triplett
2012-02-03 18:00             ` Paul E. McKenney
2012-02-02 22:47 ` [PATCH RFC 0/41] RCU commits for 3.4 Kevin Hilman
2012-02-02 23:58   ` Paul E. McKenney
2012-02-03 19:54     ` Kevin Hilman
2012-02-06  7:04       ` Paul E. McKenney

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