Messages in this thread |  | | Subject | Re: [RFC 1/3] Introduce latency-tolerance as an per-task attribute | From | Parth Shah <> | Date | Tue, 3 Dec 2019 21:17:11 +0530 |
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On 12/3/19 2:06 PM, Qais Yousef wrote: > 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 :)
Sure. Will add some text here.
> > -- > 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 >>
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