lkml.org 
[lkml]   [2019]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC 1/3] Introduce latency-tolerance as an per-task attribute
On 11/25/19 15:16, Parth Shah wrote:
> Latency-tolerance indicates the latency requirements of a task with respect
> to the other tasks in the system. The value of the attribute can be within
> the range of [-20, 19] both inclusive to be in-line with the values just
> like task nice values.
>
> latency_tolerance = -20 indicates the task to have the least latency as
> compared to the tasks having latency_tolerance = +19.
>
> The latency_tolerance may affect only the CFS SCHED_CLASS by getting
> latency requirements from the userspace.
>
> Signed-off-by: Parth Shah <parth@linux.ibm.com>
> ---
> include/linux/sched.h | 3 +++
> include/linux/sched/latency_tolerance.h | 13 +++++++++++++
> 2 files changed, 16 insertions(+)
> create mode 100644 include/linux/sched/latency_tolerance.h
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 2c2e56bd8913..bcc1c1d0856d 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -25,6 +25,7 @@
> #include <linux/resource.h>
> #include <linux/latencytop.h>
> #include <linux/sched/prio.h>
> +#include <linux/sched/latency_tolerance.h>
> #include <linux/sched/types.h>
> #include <linux/signal_types.h>
> #include <linux/mm_types_task.h>
> @@ -666,6 +667,8 @@ struct task_struct {
> #endif
> int on_rq;
>
> + int latency_tolerance;
> +
> int prio;
> int static_prio;
> int normal_prio;
> diff --git a/include/linux/sched/latency_tolerance.h b/include/linux/sched/latency_tolerance.h
> new file mode 100644
> index 000000000000..7a00abe05bc4
> --- /dev/null
> +++ b/include/linux/sched/latency_tolerance.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_SCHED_LATENCY_TOLERANCE_H
> +#define _LINUX_SCHED_LATENCY_TOLERANCE_H

nit: Add some description here explaining what latency tolerance is please. You
copy paste some text from your cover letter :)

--
Qais Youesf

> +
> +#define MAX_LATENCY_TOLERANCE 19
> +#define MIN_LATENCY_TOLERANCE -20
> +
> +#define LATENCY_TOLERANCE_WIDTH \
> + (MAX_LATENCY_TOLERANCE - MIN_LATENCY_TOLERANCE + 1)
> +
> +#define DEFAULT_LATENCY_TOLERANCE 0
> +
> +#endif /* _LINUX_SCHED_LATENCY_TOLERANCE_H */
> --
> 2.17.2
>

\
 
 \ /
  Last update: 2019-12-03 09:37    [W:0.090 / U:5.092 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site