Re: [PATCH tip/core/rcu 5/8] rcutorture: Print symbolic name for rcu_torture_writer_state

[Josh Triplett <josh@joshtriplett.org>]

On Fri, Dec 04, 2015 at 04:23:49PM -0800, Paul E. McKenney wrote:
> Currently, rcu_torture_writer_state is printed as an integer, which slows
> debugging.  This commit therefore prints a symbolic name in addition to
> the integer.
> 
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> ---
>  kernel/rcu/rcutorture.c | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> index d89328e260df..adbb194e2b5d 100644
> --- a/kernel/rcu/rcutorture.c
> +++ b/kernel/rcu/rcutorture.c
> @@ -162,6 +162,27 @@ static int rcu_torture_writer_state;
>  #define RTWS_SYNC		7
>  #define RTWS_STUTTER		8
>  #define RTWS_STOPPING		9
> +static char * const rcu_torture_writer_state_names[] = {

Shouldn't this use "static const char * const"?  Also, see below.

> +	"RTWS_FIXED_DELAY",
> +	"RTWS_DELAY",
> +	"RTWS_REPLACE",
> +	"RTWS_DEF_FREE",
> +	"RTWS_EXP_SYNC",
> +	"RTWS_COND_GET",
> +	"RTWS_COND_SYNC",
> +	"RTWS_SYNC",
> +	"RTWS_STUTTER",
> +	"RTWS_STOPPING",
> +};
> +
> +char *rcu_torture_writer_state_getname(void)

This should return "const char *", I think.

> +{
> +	unsigned int i = READ_ONCE(rcu_torture_writer_state);
> +
> +	if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
> +		return "???";
> +	return rcu_torture_writer_state_names[i];
> +}
>  
>  #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
>  #define RCUTORTURE_RUNNABLE_INIT 1
> @@ -1307,7 +1328,8 @@ rcu_torture_stats_print(void)
>  
>  		rcutorture_get_gp_data(cur_ops->ttype,
>  				       &flags, &gpnum, &completed);
> -		pr_alert("??? Writer stall state %d g%lu c%lu f%#x\n",
> +		pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x\n",
> +			 rcu_torture_writer_state_getname(),
>  			 rcu_torture_writer_state,
>  			 gpnum, completed, flags);
>  		show_rcu_gp_kthreads();
> -- 
> 2.5.2
>