Re: [RFC][PATCH 5/9] irq_work: Provide irq_work_queue_remote()

[Paul E. McKenney]

On Wed, Jul 22, 2020 at 05:01:54PM +0200, Peter Zijlstra wrote:
> While the traditional irq_work relies on the ability to self-IPI, it
> makes sense to provide an unconditional irq_work_queue_remote()
> interface.
> 
> This can be used to replace the plagued smp_call_function_single_async().
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
>  include/linux/irq_work.h |   17 ++++--
>  kernel/irq_work.c        |  129 ++++++++++++++++++++++++++++-------------------
>  kernel/rcu/tree.c        |    6 +-
>  3 files changed, 95 insertions(+), 57 deletions(-)

[ . . . ]

> --- a/kernel/irq_work.c
> +++ b/kernel/irq_work.c

[ . . . ]

> @@ -196,17 +237,5 @@ void irq_work_tick(void)
>  	irq_work_run_list(this_cpu_ptr(&lazy_list));
>  }
>  
> -/*
> - * Synchronize against the irq_work @entry, ensures the entry is not
> - * currently in use.
> - */
> -void irq_work_sync(struct irq_work *work)
> -{
> -	lockdep_assert_irqs_enabled();
> -
> -	while (irq_work_is_busy(work))
> -		cpu_relax();
> -}
> -EXPORT_SYMBOL_GPL(irq_work_sync);
> -
>  #endif /* CONFIG_IRQ_WORK */
> +

FYI, "git am" complains about this blank line.

						Thanx, Paul