2020-05-25 04:41:32

by Joel Fernandes

Subject: [PATCH 1/2] rcuperf: Remove useless while loops around wait_event

wait_event() already retries if the condition for the wake up is not
satisifed after wake up. Remove them from the rcuperf test.

Signed-off-by: Joel Fernandes (Google) <[email protected]>

---
kernel/rcu/rcuperf.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index 16dd1e6b7c09f..246da8fe199e8 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -576,11 +576,8 @@ static int compute_real(int n)
static int
rcu_perf_shutdown(void *arg)
{
- do {
- wait_event(shutdown_wq,
- atomic_read(&n_rcu_perf_writer_finished) >=
- nrealwriters);
- } while (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters);
+ wait_event(shutdown_wq,
+ atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters);
smp_mb(); /* Wake before output. */
rcu_perf_cleanup();
kernel_power_off();
@@ -693,11 +690,8 @@ kfree_perf_cleanup(void)
static int
kfree_perf_shutdown(void *arg)
{
- do {
- wait_event(shutdown_wq,
- atomic_read(&n_kfree_perf_thread_ended) >=
- kfree_nrealthreads);
- } while (atomic_read(&n_kfree_perf_thread_ended) < kfree_nrealthreads);
+ wait_event(shutdown_wq,
+ atomic_read(&n_kfree_perf_thread_ended) >= kfree_nrealthreads);

smp_mb(); /* Wake before output. */

--
2.27.0.rc0.183.gde8f92d652-goog

2020-05-25 21:46:06

by Paul E. McKenney

Subject: Re: [PATCH 1/2] rcuperf: Remove useless while loops around wait_event

On Mon, May 25, 2020 at 12:36:47AM -0400, Joel Fernandes (Google) wrote:
> wait_event() already retries if the condition for the wake up is not
> satisifed after wake up. Remove them from the rcuperf test.
>
> Signed-off-by: Joel Fernandes (Google) <[email protected]>

Queued the series, thank you, Joel!

Thanx, Paul

> ---
> kernel/rcu/rcuperf.c | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> index 16dd1e6b7c09f..246da8fe199e8 100644
> --- a/kernel/rcu/rcuperf.c
> +++ b/kernel/rcu/rcuperf.c
> @@ -576,11 +576,8 @@ static int compute_real(int n)
> static int
> rcu_perf_shutdown(void *arg)
> {
> - do {
> - wait_event(shutdown_wq,
> - atomic_read(&n_rcu_perf_writer_finished) >=
> - nrealwriters);
> - } while (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters);
> + wait_event(shutdown_wq,
> + atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters);
> smp_mb(); /* Wake before output. */
> rcu_perf_cleanup();
> kernel_power_off();
> @@ -693,11 +690,8 @@ kfree_perf_cleanup(void)
> static int
> kfree_perf_shutdown(void *arg)
> {
> - do {
> - wait_event(shutdown_wq,
> - atomic_read(&n_kfree_perf_thread_ended) >=
> - kfree_nrealthreads);
> - } while (atomic_read(&n_kfree_perf_thread_ended) < kfree_nrealthreads);
> + wait_event(shutdown_wq,
> + atomic_read(&n_kfree_perf_thread_ended) >= kfree_nrealthreads);
>
> smp_mb(); /* Wake before output. */
>
> --
> 2.27.0.rc0.183.gde8f92d652-goog
>