Re: [PATCH] blk-mq: make synchronous hw_queue runs RT friendly
From: Christoph Hellwig
Date: Mon Dec 13 2021 - 08:07:11 EST
> +#ifndef CONFIG_PREEMPT_RT
Please don't add these silly inverted ifdefs.
> +static inline void blk_mq_start_sync_run_hw_queue(void)
> +{
> + preempt_disable();
> +}
> +static inline void blk_mq_end_sync_run_hw_queue(void)
> +{
> + preempt_enable();
> +}
> +#else
> +static inline void blk_mq_start_sync_run_hw_queue(void)
> +{
> + migrate_disable();
> +}
> +static inline void blk_mq_end_sync_run_hw_queue(void)
> +{
> + migrate_enable();
> +}
> +#endif
But more importantly: why isn't migrate_disable/enable doing the right
thing for !PREEMPT_RT to avoid this mess?