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

Paul E. McKenney
2015-12-06T01:45:43Z

On Fri, Dec 04, 2015 at 05:02:21PM -0800, Josh Triplett wrote:
> 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.

Can't hurt...

> > + "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.

Yes, especially once I had made the earlier change. Also made this
function be static while I was at it.

Thanx, Paul

> > +{
> > + 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
> >
>