Re: [PATCH 4/4] block: update cached timestamp post schedule/preemption

[Johannes Thumshirn <Johannes.Thumshirn@xxxxxxx>]

On 26.01.24 22:39, Jens Axboe wrote:
>   static void sched_update_worker(struct task_struct *tsk)
>   {
> -	if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
> +	if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER | PF_BLOCK_TS)) {
> +		if (tsk->flags & PF_BLOCK_TS)
> +			blk_plug_invalidate_ts(tsk);
>   		if (tsk->flags & PF_WQ_WORKER)
>   			wq_worker_running(tsk);
> -		else
> +		else if (tsk->flags & PF_IO_WORKER)
>   			io_wq_worker_running(tsk);
>   	}
>   }


Why the nested if? Isn't that more readable:

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9116bcc90346..74beb0126da6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6787,12 +6787,12 @@ static inline void sched_submit_work(struct 
task_struct *tsk)

  static void sched_update_worker(struct task_struct *tsk)
  {
-       if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
-               if (tsk->flags & PF_WQ_WORKER)
-                       wq_worker_running(tsk);
-               else
-                       io_wq_worker_running(tsk);
-       }
+       if (tsk->flags & PF_BLOCK_TS)
+               blk_plug_invalidate_ts(tsk);
+       if (tsk->flags & PF_WQ_WORKER)
+               wq_worker_running(tsk);
+       else if (tsk->flags & PF_IO_WORKER)
+               io_wq_worker_running(tsk);
  }

  static __always_inline void __schedule_loop(unsigned int sched_mode)