Re: [PATCH tip/core/rcu 4/4] rcu: Make rcutorture's shuffler task shuffle recently added tasks

[Josh Triplett <josh@joshtriplett.org>]

On Sat, Jan 26, 2013 at 04:05:20PM -0800, Paul E. McKenney wrote:
> From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> 
> A number of kthreads have been added to rcutorture, but the shuffler
> task was not informed of them, and thus did not shuffle them.  This
> commit therefore adds the requisite shuffling.
> 
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This also makes an unrelated semantic change, and several unrelated
whitespace changes.

> ---
>  kernel/rcutorture.c |   24 ++++++++++++++++++++----
>  1 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
> index a583f1c..3ebc8bf 100644
> --- a/kernel/rcutorture.c
> +++ b/kernel/rcutorture.c
> @@ -846,7 +846,7 @@ static int rcu_torture_boost(void *arg)
>  		/* Wait for the next test interval. */
>  		oldstarttime = boost_starttime;
>  		while (ULONG_CMP_LT(jiffies, oldstarttime)) {
> -			schedule_timeout_uninterruptible(1);
> +			schedule_timeout_interruptible(oldstarttime - jiffies);

This change doesn't seem related, and the commit message doesn't explain
it either.  Could you split it out into a separate commit and document
the rationale, please?

>  			rcu_stutter_wait("rcu_torture_boost");
>  			if (kthread_should_stop() ||
>  			    fullstop != FULLSTOP_DONTSTOP)
> @@ -1318,19 +1318,35 @@ static void rcu_torture_shuffle_tasks(void)
>  				set_cpus_allowed_ptr(reader_tasks[i],
>  						     shuffle_tmp_mask);
>  	}
> -
>  	if (fakewriter_tasks) {
>  		for (i = 0; i < nfakewriters; i++)
>  			if (fakewriter_tasks[i])
>  				set_cpus_allowed_ptr(fakewriter_tasks[i],
>  						     shuffle_tmp_mask);
>  	}
> -
>  	if (writer_task)
>  		set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask);
> -

These three whitespace changes seem unrelated as well.

>  	if (stats_task)
>  		set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask);
> +	if (stutter_task)
> +		set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask);
> +	if (fqs_task)
> +		set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask);
> +	if (shutdown_task)
> +		set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask);
> +#ifdef CONFIG_HOTPLUG_CPU
> +	if (onoff_task)
> +		set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask);
> +#endif /* #ifdef CONFIG_HOTPLUG_CPU */
> +	if (stall_task)
> +		set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask);
> +	if (barrier_cbs_tasks)
> +		for (i = 0; i < n_barrier_cbs; i++)
> +			if (barrier_cbs_tasks[i])
> +				set_cpus_allowed_ptr(barrier_cbs_tasks[i],
> +						     shuffle_tmp_mask);
> +	if (barrier_task)
> +		set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask);

The rest of this seems fine.

- Josh Triplett