Re: [PATCH 1/3] rcuperf: Remove unnecessary rcu_perf_writer_state variable

From: Paul E. McKenney
Date: Sun Aug 21 2016 - 20:13:57 EST


On Sun, Aug 21, 2016 at 04:54:38PM +0900, SeongJae Park wrote:
> rcu_perf_writer_state is being written only while nobody reads it. This
> commit removes the unnecessary variable and macro constants for it.
>
> Signed-off-by: SeongJae Park <sj38.park@xxxxxxxxx>
> ---

I am keeping rcu_perf_writer_state for debugging purposes, but I pulled
in the other two patches for review and testing, thank you!

Thanx, Paul

> kernel/rcu/rcuperf.c | 16 ++--------------
> 1 file changed, 2 insertions(+), 14 deletions(-)
>
> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> index d38ab08..6025342 100644
> --- a/kernel/rcu/rcuperf.c
> +++ b/kernel/rcu/rcuperf.c
> @@ -86,13 +86,6 @@ static u64 t_rcu_perf_writer_finished;
> static unsigned long b_rcu_perf_writer_started;
> static unsigned long b_rcu_perf_writer_finished;
>
> -static int rcu_perf_writer_state;
> -#define RTWS_INIT 0
> -#define RTWS_EXP_SYNC 1
> -#define RTWS_SYNC 2
> -#define RTWS_IDLE 2
> -#define RTWS_STOPPING 3
> -
> #define MAX_MEAS 10000
> #define MIN_MEAS 100
>
> @@ -381,14 +374,10 @@ rcu_perf_writer(void *arg)
> do {
> wdp = &wdpp[i];
> *wdp = ktime_get_mono_fast_ns();
> - if (gp_exp) {
> - rcu_perf_writer_state = RTWS_EXP_SYNC;
> + if (gp_exp)
> cur_ops->exp_sync();
> - } else {
> - rcu_perf_writer_state = RTWS_SYNC;
> + else
> cur_ops->sync();
> - }
> - rcu_perf_writer_state = RTWS_IDLE;
> t = ktime_get_mono_fast_ns();
> *wdp = t - *wdp;
> i_max = i;
> @@ -429,7 +418,6 @@ rcu_perf_writer(void *arg)
> i++;
> rcu_perf_wait_shutdown();
> } while (!torture_must_stop());
> - rcu_perf_writer_state = RTWS_STOPPING;
> writer_n_durations[me] = i_max;
> torture_kthread_stopping("rcu_perf_writer");
> return 0;
> --
> 1.9.1
>