105 lines
3.6 KiB
Diff
105 lines
3.6 KiB
Diff
From 44a6d7ca11b601b34724dc41e086576499a096bd Mon Sep 17 00:00:00 2001
|
|
From: "Jan Alexander Steffens (heftig)" <heftig@archlinux.org>
|
|
Date: Tue, 31 Oct 2023 19:03:10 +0100
|
|
Subject: ZEN: INTERACTIVE: Tune EEVDF for interactivity
|
|
|
|
5.7:
|
|
Take "sysctl_sched_nr_migrate" tune from early XanMod builds of 128. As
|
|
of 5.7, XanMod uses 256 but that may affect applications that require
|
|
timely response to IRQs.
|
|
|
|
5.15:
|
|
Per [a comment][1] on our ZEN INTERACTIVE commit, reducing the cost of
|
|
migration causes the system less responsive under high load. Most
|
|
likely the combination of reduced migration cost + the higher number of
|
|
tasks that can be migrated at once contributes to this.
|
|
|
|
To better handle this situation, restore the mainline migration cost
|
|
value and also reduce the max number of tasks that can be migrated in
|
|
batch from 128 to 64.
|
|
|
|
If this doesn't help, we'll restore the reduced migration cost and keep
|
|
total number of tasks that can be migrated at once to 32.
|
|
|
|
[1]: https://github.com/zen-kernel/zen-kernel/commit/be5ba234ca0a5aabe74bfc7e1f636f085bd3823c#commitcomment-63159674
|
|
|
|
6.6:
|
|
Port the tuning to EEVDF, which removed a couple of settings.
|
|
|
|
6.7:
|
|
Instead of increasing the number of tasks that migrate at once, migrate
|
|
the amount acceptable for PREEMPT_RT, but reduce the cost so migrations
|
|
occur more often.
|
|
|
|
This should make CFS/EEVDF behave more like out-of-tree schedulers that
|
|
aggressively use idle cores to reduce latency, but without the jank
|
|
caused by rebalancing too many tasks at once.
|
|
---
|
|
init/Kconfig | 7 +++++++
|
|
kernel/sched/fair.c | 13 +++++++++++++
|
|
kernel/sched/sched.h | 2 +-
|
|
3 files changed, 21 insertions(+), 1 deletion(-)
|
|
|
|
--- a/init/Kconfig
|
|
+++ b/init/Kconfig
|
|
@@ -159,6 +159,13 @@ config ZEN_INTERACTIVE
|
|
Background-reclaim hugepages...: no -> yes
|
|
MG-LRU minimum cache TTL.......: 0 -> 1000 ms
|
|
|
|
+ --- EEVDF CPU Scheduler --------------------------------
|
|
+
|
|
+ Minimal granularity............: 0.75 -> 0.4 ms
|
|
+ Migration cost.................: 0.5 -> 0.25 ms
|
|
+ Bandwidth slice size...........: 5 -> 3 ms
|
|
+ Task rebalancing threshold.....: 32 -> 8
|
|
+
|
|
config BROKEN
|
|
bool
|
|
|
|
--- a/kernel/sched/fair.c
|
|
+++ b/kernel/sched/fair.c
|
|
@@ -73,10 +73,19 @@ unsigned int sysctl_sched_tunable_scalin
|
|
*
|
|
* (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
|
|
*/
|
|
+#ifdef CONFIG_ZEN_INTERACTIVE
|
|
+unsigned int sysctl_sched_base_slice = 400000ULL;
|
|
+static unsigned int normalized_sysctl_sched_base_slice = 400000ULL;
|
|
+#else
|
|
unsigned int sysctl_sched_base_slice = 750000ULL;
|
|
static unsigned int normalized_sysctl_sched_base_slice = 750000ULL;
|
|
+#endif
|
|
|
|
+#ifdef CONFIG_ZEN_INTERACTIVE
|
|
+const_debug unsigned int sysctl_sched_migration_cost = 250000UL;
|
|
+#else
|
|
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
|
|
+#endif
|
|
|
|
static int __init setup_sched_thermal_decay_shift(char *str)
|
|
{
|
|
@@ -121,8 +130,12 @@ int __weak arch_asym_cpu_priority(int cp
|
|
*
|
|
* (default: 5 msec, units: microseconds)
|
|
*/
|
|
+#ifdef CONFIG_ZEN_INTERACTIVE
|
|
+static unsigned int sysctl_sched_cfs_bandwidth_slice = 3000UL;
|
|
+#else
|
|
static unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
|
|
#endif
|
|
+#endif
|
|
|
|
#ifdef CONFIG_NUMA_BALANCING
|
|
/* Restrict the NUMA promotion throughput (MB/s) for each target node. */
|
|
--- a/kernel/sched/sched.h
|
|
+++ b/kernel/sched/sched.h
|
|
@@ -2591,7 +2591,7 @@ extern void deactivate_task(struct rq *r
|
|
|
|
extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags);
|
|
|
|
-#ifdef CONFIG_PREEMPT_RT
|
|
+#if defined(CONFIG_PREEMPT_RT) || defined(CONFIG_ZEN_INTERACTIVE)
|
|
# define SCHED_NR_MIGRATE_BREAK 8
|
|
#else
|
|
# define SCHED_NR_MIGRATE_BREAK 32
|