Re: [PATCH 0/2] vhost: improve livepatch switching for heavily loaded vhost worker kthreads

[Peter Zijlstra]

On Mon, Jan 30, 2023 at 11:59:30AM -0800, Josh Poimboeuf wrote:

> @@ -8662,16 +8665,19 @@ void sched_dynamic_update(int mode)
>  
>  	switch (mode) {
>  	case preempt_dynamic_none:
> -		preempt_dynamic_enable(cond_resched);
> +		if (!klp_override)
> +			preempt_dynamic_enable(cond_resched);
>  		preempt_dynamic_disable(might_resched);
>  		preempt_dynamic_disable(preempt_schedule);
>  		preempt_dynamic_disable(preempt_schedule_notrace);
>  		preempt_dynamic_disable(irqentry_exit_cond_resched);
> +		//FIXME avoid printk for klp restore

		if (mode != preempt_dynamic_mode)

>  		pr_info("Dynamic Preempt: none\n");
>  		break;
>  
>  	case preempt_dynamic_voluntary:
> -		preempt_dynamic_enable(cond_resched);
> +		if (!klp_override)
> +			preempt_dynamic_enable(cond_resched);
>  		preempt_dynamic_enable(might_resched);
>  		preempt_dynamic_disable(preempt_schedule);
>  		preempt_dynamic_disable(preempt_schedule_notrace);