sched_priority = 1 is enough to dramatically reduce latency on have system load produced by tasks with default user space prio.
Signed-off-by: Oleksij Rempel <[email protected]> --- drivers/tty/tty_buffer.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 18bd7f48a319..7cf42f6570a0 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -13,11 +13,13 @@ #include <linux/string.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/sched/rt.h> #include <linux/wait.h> #include <linux/bitops.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/ratelimit.h> +#include <uapi/linux/sched/types.h> #define MIN_TTYB_SIZE 256 @@ -567,7 +569,15 @@ bool tty_buffer_queue_work(struct tty_port *port) void tty_buffer_init_kthread(void) { - kthread_run(kthread_worker_fn, &tty_buffer_worker, "tty"); + struct sched_param param = { .sched_priority = 1 }; + struct task_struct *kworker_task; + + kworker_task = kthread_run(kthread_worker_fn, &tty_buffer_worker, "tty"); + if (IS_ERR(kworker_task)) { + pr_err("failed to create message pump task\n"); + return; + } + sched_setscheduler(kworker_task, SCHED_FIFO, ¶m); } /** -- 2.19.1
