1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
From 823fb7f07b91a3c7b7d1a4d6a3532a4e4c337e70 Mon Sep 17 00:00:00 2001
From: Masahito S <firelzrd@gmail.com>
Date: Fri, 7 Apr 2023 00:57:07 +0900
Subject: [PATCH] constgran v2 sched: Make latency / granularity constant
tunable_scaling = 1 (logarithmic) -> 0 (constant) latency_ns = variable
6-24ms -> constant 12.8ms min_granularity_ns = variable 0.75-3ms -> constant
1.6ms wakeup_granularity_ns = variable 1-4ms -> constant 9.6ms
---
kernel/sched/fair.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 44de1349c..3ad82e1ab 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -36,10 +36,16 @@
* (to see the precise effective timeslice length of your workload,
* run vmstat and monitor the context-switches (cs) field)
*
- * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 12.8ms constant, units: nanoseconds)
+ * (CFS default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
*/
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_latency = 12800000ULL;
+static unsigned int normalized_sysctl_sched_latency = 12800000ULL;
+#else // CONFIG_SCHED_BORE
unsigned int sysctl_sched_latency = 6000000ULL;
static unsigned int normalized_sysctl_sched_latency = 6000000ULL;
+#endif // CONFIG_SCHED_BORE
/*
* The initial- and re-scaling of tunables is configurable
@@ -50,17 +56,28 @@ static unsigned int normalized_sysctl_sched_latency = 6000000ULL;
* SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
* SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
*
- * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
+ * (BORE default SCHED_TUNABLESCALING_NONE = *1 constant)
+ * (CFS default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
*/
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
+#else // CONFIG_SCHED_BORE
unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;
+#endif // CONFIG_SCHED_BORE
/*
* Minimal preemption granularity for CPU-bound tasks:
*
- * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 1.6 msec constant, units: nanoseconds)
+ * (CFS default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_min_granularity = 1600000ULL;
+static unsigned int normalized_sysctl_sched_min_granularity = 1600000ULL;
+#else // CONFIG_SCHED_BORE
unsigned int sysctl_sched_min_granularity = 750000ULL;
static unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
+#endif // CONFIG_SCHED_BORE
/*
* This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity
@@ -80,10 +97,16 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*
- * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 9.6 msec constant, units: nanoseconds)
+ * (CFS default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_wakeup_granularity = 9600000UL;
+static unsigned int normalized_sysctl_sched_wakeup_granularity = 9600000UL;
+#else // CONFIG_SCHED_BORE
unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
+#endif // CONFIG_SCHED_BORE
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
--
2.25.1
|