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|
From ed828209e2e391d7155e153267df515ffffdefb2 Mon Sep 17 00:00:00 2001
From: Piotr Gorski <lucjan.lucjanov@gmail.com>
Date: Mon, 4 Mar 2024 12:48:19 +0100
Subject: [PATCH] bore
Signed-off-by: Piotr Gorski <lucjan.lucjanov@gmail.com>
---
include/linux/sched.h | 12 ++
init/Kconfig | 19 +++
kernel/sched/core.c | 148 ++++++++++++++++++++
kernel/sched/debug.c | 61 +++++++-
kernel/sched/fair.c | 302 ++++++++++++++++++++++++++++++++++++++--
kernel/sched/features.h | 4 +
kernel/sched/sched.h | 7 +
7 files changed, 538 insertions(+), 15 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 292c31697..5abe14fc1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -562,6 +562,18 @@ struct sched_entity {
u64 sum_exec_runtime;
u64 prev_sum_exec_runtime;
u64 vruntime;
+#ifdef CONFIG_SCHED_BORE
+ u64 burst_time;
+ u8 prev_burst_penalty;
+ u8 curr_burst_penalty;
+ u8 burst_penalty;
+ u8 burst_score;
+ u32 burst_load;
+ bool on_cfs_rq;
+ u8 child_burst;
+ u32 child_burst_cnt;
+ u64 child_burst_last_cached;
+#endif // CONFIG_SCHED_BORE
s64 vlag;
u64 slice;
diff --git a/init/Kconfig b/init/Kconfig
index bfde8189c..2258b8ef5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1267,6 +1267,25 @@ config CHECKPOINT_RESTORE
If unsure, say N here.
+config SCHED_BORE
+ bool "Burst-Oriented Response Enhancer"
+ default y
+ help
+ In Desktop and Mobile computing, one might prefer interactive
+ tasks to keep responsive no matter what they run in the background.
+
+ Enabling this kernel feature modifies the scheduler to discriminate
+ tasks by their burst time (runtime since it last went sleeping or
+ yielding state) and prioritize those that run less bursty.
+ Such tasks usually include window compositor, widgets backend,
+ terminal emulator, video playback, games and so on.
+ With a little impact to scheduling fairness, it may improve
+ responsiveness especially under heavy background workload.
+
+ You can turn it off by setting the sysctl kernel.sched_bore = 0.
+
+ If unsure, say Y here.
+
config SCHED_AUTOGROUP
bool "Automatic process group scheduling"
select CGROUPS
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a708d225c..31f5e8a73 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4480,6 +4480,143 @@ int wake_up_state(struct task_struct *p, unsigned int state)
return try_to_wake_up(p, state, 0);
}
+#ifdef CONFIG_SCHED_BORE
+extern bool sched_bore;
+extern u8 sched_burst_fork_atavistic;
+extern uint sched_burst_cache_lifetime;
+
+static void __init sched_init_bore(void) {
+ init_task.se.burst_time = 0;
+ init_task.se.prev_burst_penalty = 0;
+ init_task.se.curr_burst_penalty = 0;
+ init_task.se.burst_penalty = 0;
+ init_task.se.burst_score = 0;
+ init_task.se.on_cfs_rq = false;
+ init_task.se.child_burst_last_cached = 0;
+ init_task.se.burst_load = 0;
+}
+
+void inline sched_fork_bore(struct task_struct *p) {
+ p->se.burst_time = 0;
+ p->se.curr_burst_penalty = 0;
+ p->se.burst_score = 0;
+ p->se.on_cfs_rq = false;
+ p->se.child_burst_last_cached = 0;
+ p->se.burst_load = 0;
+}
+
+static u32 count_child_tasks(struct task_struct *p) {
+ struct task_struct *child;
+ u32 cnt = 0;
+ list_for_each_entry(child, &p->children, sibling) {cnt++;}
+ return cnt;
+}
+
+static inline bool task_is_inheritable(struct task_struct *p) {
+ return (p->sched_class == &fair_sched_class);
+}
+
+static inline bool child_burst_cache_expired(struct task_struct *p, u64 now) {
+ u64 expiration_time =
+ p->se.child_burst_last_cached + sched_burst_cache_lifetime;
+ return ((s64)(expiration_time - now) < 0);
+}
+
+static void __update_child_burst_cache(
+ struct task_struct *p, u32 cnt, u32 sum, u64 now) {
+ u8 avg = 0;
+ if (cnt) avg = sum / cnt;
+ p->se.child_burst = max(avg, p->se.burst_penalty);
+ p->se.child_burst_cnt = cnt;
+ p->se.child_burst_last_cached = now;
+}
+
+static inline void update_child_burst_direct(struct task_struct *p, u64 now) {
+ struct task_struct *child;
+ u32 cnt = 0;
+ u32 sum = 0;
+
+ list_for_each_entry(child, &p->children, sibling) {
+ if (!task_is_inheritable(child)) continue;
+ cnt++;
+ sum += child->se.burst_penalty;
+ }
+
+ __update_child_burst_cache(p, cnt, sum, now);
+}
+
+static inline u8 __inherit_burst_direct(struct task_struct *p, u64 now) {
+ struct task_struct *parent = p->real_parent;
+ if (child_burst_cache_expired(parent, now))
+ update_child_burst_direct(parent, now);
+
+ return parent->se.child_burst;
+}
+
+static void update_child_burst_topological(
+ struct task_struct *p, u64 now, u32 depth, u32 *acnt, u32 *asum) {
+ struct task_struct *child, *dec;
+ u32 cnt = 0, dcnt = 0;
+ u32 sum = 0;
+
+ list_for_each_entry(child, &p->children, sibling) {
+ dec = child;
+ while ((dcnt = count_child_tasks(dec)) == 1)
+ dec = list_first_entry(&dec->children, struct task_struct, sibling);
+
+ if (!dcnt || !depth) {
+ if (!task_is_inheritable(dec)) continue;
+ cnt++;
+ sum += dec->se.burst_penalty;
+ continue;
+ }
+ if (!child_burst_cache_expired(dec, now)) {
+ cnt += dec->se.child_burst_cnt;
+ sum += (u32)dec->se.child_burst * dec->se.child_burst_cnt;
+ continue;
+ }
+ update_child_burst_topological(dec, now, depth - 1, &cnt, &sum);
+ }
+
+ __update_child_burst_cache(p, cnt, sum, now);
+ *acnt += cnt;
+ *asum += sum;
+}
+
+static inline u8 __inherit_burst_topological(struct task_struct *p, u64 now) {
+ struct task_struct *anc = p->real_parent;
+ u32 cnt = 0, sum = 0;
+
+ while (anc->real_parent != anc && count_child_tasks(anc) == 1)
+ anc = anc->real_parent;
+
+ if (child_burst_cache_expired(anc, now))
+ update_child_burst_topological(
+ anc, now, sched_burst_fork_atavistic - 1, &cnt, &sum);
+
+ return anc->se.child_burst;
+}
+
+static inline void inherit_burst(struct task_struct *p) {
+ u8 burst_cache;
+ u64 now = ktime_get_ns();
+
+ read_lock(&tasklist_lock);
+ burst_cache = likely(sched_burst_fork_atavistic)?
+ __inherit_burst_topological(p, now):
+ __inherit_burst_direct(p, now);
+ read_unlock(&tasklist_lock);
+
+ p->se.prev_burst_penalty = max(p->se.prev_burst_penalty, burst_cache);
+}
+
+static void sched_post_fork_bore(struct task_struct *p) {
+ if (p->sched_class == &fair_sched_class && likely(sched_bore))
+ inherit_burst(p);
+ p->se.burst_penalty = p->se.prev_burst_penalty;
+}
+#endif // CONFIG_SCHED_BORE
+
/*
* Perform scheduler related setup for a newly forked process p.
* p is forked by current.
@@ -4496,6 +4633,9 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
p->se.prev_sum_exec_runtime = 0;
p->se.nr_migrations = 0;
p->se.vruntime = 0;
+#ifdef CONFIG_SCHED_BORE
+ sched_fork_bore(p);
+#endif // CONFIG_SCHED_BORE
p->se.vlag = 0;
p->se.slice = sysctl_sched_base_slice;
INIT_LIST_HEAD(&p->se.group_node);
@@ -4815,6 +4955,9 @@ void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs)
void sched_post_fork(struct task_struct *p)
{
+#ifdef CONFIG_SCHED_BORE
+ sched_post_fork_bore(p);
+#endif // CONFIG_SCHED_BORE
uclamp_post_fork(p);
}
@@ -9885,6 +10028,11 @@ void __init sched_init(void)
BUG_ON(&dl_sched_class != &stop_sched_class + 1);
#endif
+#ifdef CONFIG_SCHED_BORE
+ sched_init_bore();
+ printk(KERN_INFO "BORE (Burst-Oriented Response Enhancer) CPU Scheduler modification 4.5.1 by Masahito Suzuki");
+#endif // CONFIG_SCHED_BORE
+
wait_bit_init();
#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 4580a4507..033cbe7d3 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -167,7 +167,52 @@ static const struct file_operations sched_feat_fops = {
};
#ifdef CONFIG_SMP
+#ifdef CONFIG_SCHED_BORE
+static ssize_t sched_min_base_slice_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[16];
+ unsigned int value;
+
+ if (cnt > 15)
+ cnt = 15;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+ buf[cnt] = '\0';
+
+ if (kstrtouint(buf, 10, &value))
+ return -EINVAL;
+ if (!value)
+ return -EINVAL;
+
+ sysctl_sched_min_base_slice = value;
+ sched_update_min_base_slice();
+
+ *ppos += cnt;
+ return cnt;
+}
+
+static int sched_min_base_slice_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "%d\n", sysctl_sched_min_base_slice);
+ return 0;
+}
+
+static int sched_min_base_slice_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_min_base_slice_show, NULL);
+}
+
+static const struct file_operations sched_min_base_slice_fops = {
+ .open = sched_min_base_slice_open,
+ .write = sched_min_base_slice_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#else // !CONFIG_SCHED_BORE
static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
@@ -213,7 +258,7 @@ static const struct file_operations sched_scaling_fops = {
.llseek = seq_lseek,
.release = single_release,
};
-
+#endif // CONFIG_SCHED_BORE
#endif /* SMP */
#ifdef CONFIG_PREEMPT_DYNAMIC
@@ -347,13 +392,20 @@ static __init int sched_init_debug(void)
debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
#endif
+#ifdef CONFIG_SCHED_BORE
+ debugfs_create_file("min_base_slice_ns", 0644, debugfs_sched, NULL, &sched_min_base_slice_fops);
+ debugfs_create_u32("base_slice_ns", 0400, debugfs_sched, &sysctl_sched_base_slice);
+#else // !CONFIG_SCHED_BORE
debugfs_create_u32("base_slice_ns", 0644, debugfs_sched, &sysctl_sched_base_slice);
+#endif // CONFIG_SCHED_BORE
debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms);
debugfs_create_u32("latency_warn_once", 0644, debugfs_sched, &sysctl_resched_latency_warn_once);
#ifdef CONFIG_SMP
+#if !defined(CONFIG_SCHED_BORE)
debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops);
+#endif // CONFIG_SCHED_BORE
debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);
debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);
@@ -595,6 +647,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)),
SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime)));
+#ifdef CONFIG_SCHED_BORE
+ SEQ_printf(m, " %2d", p->se.burst_score);
+#endif // CONFIG_SCHED_BORE
#ifdef CONFIG_NUMA_BALANCING
SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
#endif
@@ -1063,6 +1118,10 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
P(se.load.weight);
#ifdef CONFIG_SMP
+#ifdef CONFIG_SCHED_BORE
+ P(se.burst_load);
+ P(se.burst_score);
+#endif // CONFIG_SCHED_BORE
P(se.avg.load_sum);
P(se.avg.runnable_sum);
P(se.avg.util_sum);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7ac9f4b1d..8f7694f05 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -19,6 +19,9 @@
*
* Adaptive scheduling granularity, math enhancements by Peter Zijlstra
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
+ *
+ * Burst-Oriented Response Enhancer (BORE) CPU Scheduler
+ * Copyright (C) 2021-2024 Masahito Suzuki <firelzrd@gmail.com>
*/
#include <linux/energy_model.h>
#include <linux/mmap_lock.h>
@@ -64,20 +67,129 @@
* 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)
+ * (EEVDF 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: max(1 sec / HZ, min_base_slice) constant, units: nanoseconds)
+ * (EEVDF default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_base_slice = 1000000000ULL / HZ;
+static unsigned int configured_sched_base_slice = 1000000000ULL / HZ;
+unsigned int sysctl_sched_min_base_slice = 2000000ULL;
+#else // !CONFIG_SCHED_BORE
unsigned int sysctl_sched_base_slice = 750000ULL;
static unsigned int normalized_sysctl_sched_base_slice = 750000ULL;
+#endif // CONFIG_SCHED_BORE
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+#ifdef CONFIG_SCHED_BORE
+u8 __read_mostly sched_bore = 1;
+u8 __read_mostly sched_burst_score_rounding = 0;
+u8 __read_mostly sched_burst_smoothness_long = 1;
+u8 __read_mostly sched_burst_smoothness_short = 0;
+u8 __read_mostly sched_burst_fork_atavistic = 2;
+u8 __read_mostly sched_burst_penalty_offset = 22;
+uint __read_mostly sched_burst_penalty_scale = 1280;
+uint __read_mostly sched_burst_cache_lifetime = 60000000;
+u8 __read_mostly sched_vlag_deviation_limit = 11;
+static int __maybe_unused thirty_two = 32;
+static int __maybe_unused sixty_four = 64;
+static int __maybe_unused maxval_12_bits = 4095;
+
+#define MAX_BURST_PENALTY (39U <<2)
+
+static inline u32 log2plus1_u64_u32f8(u64 v) {
+ u32 msb = fls64(v);
+ s32 excess_bits = msb - 9;
+ u8 fractional = (0 <= excess_bits)? v >> excess_bits: v << -excess_bits;
+ return msb << 8 | fractional;
+}
+
+static inline u32 calc_burst_penalty(u64 burst_time) {
+ u32 greed, tolerance, penalty, scaled_penalty;
+
+ greed = log2plus1_u64_u32f8(burst_time);
+ tolerance = sched_burst_penalty_offset << 8;
+ penalty = max(0, (s32)greed - (s32)tolerance);
+ scaled_penalty = penalty * sched_burst_penalty_scale >> 16;
+
+ return min(MAX_BURST_PENALTY, scaled_penalty);
+}
+
+static inline u64 scale_slice(u64 delta, struct sched_entity *se) {
+ return mul_u64_u32_shr(delta, sched_prio_to_wmult[se->burst_score], 22);
+}
+
+static inline u64 __unscale_slice(u64 delta, u8 score) {
+ return mul_u64_u32_shr(delta, sched_prio_to_weight[score], 10);
+}
+
+static inline u64 unscale_slice(u64 delta, struct sched_entity *se) {
+ return __unscale_slice(delta, se->burst_score);
+}
+
+static void avg_vruntime_add(struct cfs_rq *cfs_rq, struct sched_entity *se);
+static void avg_vruntime_sub(struct cfs_rq *cfs_rq, struct sched_entity *se);
+
+static void update_burst_score(struct sched_entity *se) {
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ u8 prev_score = se->burst_score;
+ u32 penalty = se->burst_penalty;
+ if (sched_burst_score_rounding) penalty += 0x2U;
+ se->burst_score = penalty >> 2;
+
+ if ((se->burst_score != prev_score) && se->on_cfs_rq) {
+ avg_vruntime_sub(cfs_rq, se);
+ avg_vruntime_add(cfs_rq, se);
+ }
+}
+
+static void update_burst_penalty(struct sched_entity *se) {
+ se->curr_burst_penalty = calc_burst_penalty(se->burst_time);
+ se->burst_penalty = max(se->prev_burst_penalty, se->curr_burst_penalty);
+ update_burst_score(se);
+}
+
+static inline u32 binary_smooth(u32 new, u32 old) {
+ int increment = new - old;
+ return (0 <= increment)?
+ old + ( increment >> (int)sched_burst_smoothness_long):
+ old - (-increment >> (int)sched_burst_smoothness_short);
+}
+
+static void restart_burst(struct sched_entity *se) {
+ se->burst_penalty = se->prev_burst_penalty =
+ binary_smooth(se->curr_burst_penalty, se->prev_burst_penalty);
+ se->curr_burst_penalty = 0;
+ se->burst_time = 0;
+ update_burst_score(se);
+}
+
+static void restart_burst_rescale_deadline(struct sched_entity *se) {
+ s64 vscaled, wremain, vremain = se->deadline - se->vruntime;
+ u8 prev_score = se->burst_score;
+ restart_burst(se);
+ if (prev_score > se->burst_score) {
+ wremain = __unscale_slice(abs(vremain), prev_score);
+ vscaled = scale_slice(wremain, se);
+ if (unlikely(vremain < 0))
+ vscaled = -vscaled;
+ se->deadline = se->vruntime + vscaled;
+ }
+}
+#endif // CONFIG_SCHED_BORE
+
int sched_thermal_decay_shift;
static int __init setup_sched_thermal_decay_shift(char *str)
{
@@ -137,6 +249,87 @@ static unsigned int sysctl_numa_balancing_promote_rate_limit = 65536;
#ifdef CONFIG_SYSCTL
static struct ctl_table sched_fair_sysctls[] = {
+#ifdef CONFIG_SCHED_BORE
+ {
+ .procname = "sched_bore",
+ .data = &sched_bore,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "sched_burst_score_rounding",
+ .data = &sched_burst_score_rounding,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "sched_burst_smoothness_long",
+ .data = &sched_burst_smoothness_long,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "sched_burst_smoothness_short",
+ .data = &sched_burst_smoothness_short,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "sched_burst_fork_atavistic",
+ .data = &sched_burst_fork_atavistic,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_THREE,
+ },
+ {
+ .procname = "sched_burst_penalty_offset",
+ .data = &sched_burst_penalty_offset,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = &sixty_four,
+ },
+ {
+ .procname = "sched_burst_penalty_scale",
+ .data = &sched_burst_penalty_scale,
+ .maxlen = sizeof(uint),
+ .mode = 0644,
+ .proc_handler = proc_douintvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = &maxval_12_bits,
+ },
+ {
+ .procname = "sched_burst_cache_lifetime",
+ .data = &sched_burst_cache_lifetime,
+ .maxlen = sizeof(uint),
+ .mode = 0644,
+ .proc_handler = proc_douintvec,
+ },
+ {
+ .procname = "sched_vlag_deviation_limit",
+ .data = &sched_vlag_deviation_limit,
+ .maxlen = sizeof(u8),
+ .mode = 0644,
+ .proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = &thirty_two,
+ },
+#endif // CONFIG_SCHED_BORE
#ifdef CONFIG_CFS_BANDWIDTH
{
.procname = "sched_cfs_bandwidth_slice_us",
@@ -195,6 +388,13 @@ static inline void update_load_set(struct load_weight *lw, unsigned long w)
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
+#ifdef CONFIG_SCHED_BORE
+static void update_sysctl(void) {
+ sysctl_sched_base_slice =
+ max(sysctl_sched_min_base_slice, configured_sched_base_slice);
+}
+void sched_update_min_base_slice(void) { update_sysctl(); }
+#else // !CONFIG_SCHED_BORE
static unsigned int get_update_sysctl_factor(void)
{
unsigned int cpus = min_t(unsigned int, num_online_cpus(), 8);
@@ -225,6 +425,7 @@ static void update_sysctl(void)
SET_SYSCTL(sched_base_slice);
#undef SET_SYSCTL
}
+#endif // CONFIG_SCHED_BORE
void __init sched_init_granularity(void)
{
@@ -298,6 +499,9 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
if (unlikely(se->load.weight != NICE_0_LOAD))
delta = __calc_delta(delta, NICE_0_LOAD, &se->load);
+#ifdef CONFIG_SCHED_BORE
+ if (likely(sched_bore)) delta = scale_slice(delta, se);
+#endif // CONFIG_SCHED_BORE
return delta;
}
@@ -620,10 +824,26 @@ static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
*
* As measured, the max (key * weight) value was ~44 bits for a kernel build.
*/
+#if !defined(CONFIG_SCHED_BORE)
+#define entity_weight(se) scale_load_down(se->load.weight)
+#else // CONFIG_SCHED_BORE
+static unsigned long entity_weight(struct sched_entity *se) {
+ unsigned long weight = se->load.weight;
+ if (likely(sched_bore)) weight = unscale_slice(weight, se);
+#ifdef CONFIG_64BIT
+ weight >>= SCHED_FIXEDPOINT_SHIFT - 3;
+#endif // CONFIG_64BIT
+ return weight;
+}
+#endif // CONFIG_SCHED_BORE
+
static void
avg_vruntime_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- unsigned long weight = scale_load_down(se->load.weight);
+ unsigned long weight = entity_weight(se);
+#ifdef CONFIG_SCHED_BORE
+ se->burst_load = weight;
+#endif // CONFIG_SCHED_BORE
s64 key = entity_key(cfs_rq, se);
cfs_rq->avg_vruntime += key * weight;
@@ -633,7 +853,12 @@ avg_vruntime_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
static void
avg_vruntime_sub(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- unsigned long weight = scale_load_down(se->load.weight);
+#if !defined(CONFIG_SCHED_BORE)
+ unsigned long weight = entity_weight(se);
+#else // CONFIG_SCHED_BORE
+ unsigned long weight = se->burst_load;
+ se->burst_load = 0;
+#endif // CONFIG_SCHED_BORE
s64 key = entity_key(cfs_rq, se);
cfs_rq->avg_vruntime -= key * weight;
@@ -653,14 +878,14 @@ void avg_vruntime_update(struct cfs_rq *cfs_rq, s64 delta)
* Specifically: avg_runtime() + 0 must result in entity_eligible() := true
* For this to be so, the result of this function must have a left bias.
*/
-u64 avg_vruntime(struct cfs_rq *cfs_rq)
+static u64 avg_key(struct cfs_rq *cfs_rq)
{
struct sched_entity *curr = cfs_rq->curr;
s64 avg = cfs_rq->avg_vruntime;
long load = cfs_rq->avg_load;
if (curr && curr->on_rq) {
- unsigned long weight = scale_load_down(curr->load.weight);
+ unsigned long weight = entity_weight(curr);
avg += entity_key(cfs_rq, curr) * weight;
load += weight;
@@ -670,12 +895,15 @@ u64 avg_vruntime(struct cfs_rq *cfs_rq)
/* sign flips effective floor / ceil */
if (avg < 0)
avg -= (load - 1);
- avg = div_s64(avg, load);
+ avg = div64_s64(avg, load);
}
- return cfs_rq->min_vruntime + avg;
+ return avg;
}
+u64 avg_vruntime(struct cfs_rq *cfs_rq) {
+ return cfs_rq->min_vruntime + avg_key(cfs_rq);
+}
/*
* lag_i = S - s_i = w_i * (V - v_i)
*
@@ -700,6 +928,9 @@ static void update_entity_lag(struct cfs_rq *cfs_rq, struct sched_entity *se)
lag = avg_vruntime(cfs_rq) - se->vruntime;
limit = calc_delta_fair(max_t(u64, 2*se->slice, TICK_NSEC), se);
+#ifdef CONFIG_SCHED_BORE
+ if (likely(sched_bore)) limit >>= 1;
+#endif // CONFIG_SCHED_BORE
se->vlag = clamp(lag, -limit, limit);
}
@@ -727,7 +958,7 @@ int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se)
long load = cfs_rq->avg_load;
if (curr && curr->on_rq) {
- unsigned long weight = scale_load_down(curr->load.weight);
+ unsigned long weight = entity_weight(curr);
avg += entity_key(cfs_rq, curr) * weight;
load += weight;
@@ -819,10 +1050,16 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->min_deadline = se->deadline;
rb_add_augmented_cached(&se->run_node, &cfs_rq->tasks_timeline,
__entity_less, &min_deadline_cb);
+#ifdef CONFIG_SCHED_BORE
+ se->on_cfs_rq = true;
+#endif // CONFIG_SCHED_BORE
}
static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
+#ifdef CONFIG_SCHED_BORE
+ se->on_cfs_rq = false;
+#endif // CONFIG_SCHED_BORE
rb_erase_augmented_cached(&se->run_node, &cfs_rq->tasks_timeline,
&min_deadline_cb);
avg_vruntime_sub(cfs_rq, se);
@@ -981,6 +1218,7 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
* Scheduling class statistics methods:
*/
#ifdef CONFIG_SMP
+#if !defined(CONFIG_SCHED_BORE)
int sched_update_scaling(void)
{
unsigned int factor = get_update_sysctl_factor();
@@ -992,6 +1230,7 @@ int sched_update_scaling(void)
return 0;
}
+#endif // CONFIG_SCHED_BORE
#endif
#endif
@@ -1158,7 +1397,13 @@ static void update_curr(struct cfs_rq *cfs_rq)
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq->exec_clock, delta_exec);
+#ifdef CONFIG_SCHED_BORE
+ curr->burst_time += delta_exec;
+ update_burst_penalty(curr);
+ curr->vruntime += max(1ULL, calc_delta_fair(delta_exec, curr));
+#else // !CONFIG_SCHED_BORE
curr->vruntime += calc_delta_fair(delta_exec, curr);
+#endif // CONFIG_SCHED_BORE
update_deadline(cfs_rq, curr);
update_min_vruntime(cfs_rq);
@@ -5164,8 +5409,8 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
static void
place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
- u64 vslice, vruntime = avg_vruntime(cfs_rq);
- s64 lag = 0;
+ s64 lag = 0, key = avg_key(cfs_rq);
+ u64 vslice, vruntime = cfs_rq->min_vruntime + key;
se->slice = sysctl_sched_base_slice;
vslice = calc_delta_fair(se->slice, se);
@@ -5178,6 +5423,9 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
*
* EEVDF: placement strategy #1 / #2
*/
+#ifdef CONFIG_SCHED_BORE
+ if (unlikely(!sched_bore) || se->vlag)
+#endif // CONFIG_SCHED_BORE
if (sched_feat(PLACE_LAG) && cfs_rq->nr_running) {
struct sched_entity *curr = cfs_rq->curr;
unsigned long load;
@@ -5238,12 +5486,18 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
*/
load = cfs_rq->avg_load;
if (curr && curr->on_rq)
- load += scale_load_down(curr->load.weight);
+ load += entity_weight(curr);
- lag *= load + scale_load_down(se->load.weight);
+ lag *= load + entity_weight(se);
if (WARN_ON_ONCE(!load))
load = 1;
- lag = div_s64(lag, load);
+ lag = div64_s64(lag, load);
+#ifdef CONFIG_SCHED_BORE
+ if (likely(sched_bore)) {
+ s64 limit = vslice << sched_vlag_deviation_limit;
+ lag = clamp(lag, -limit, limit);
+ }
+#endif // CONFIG_SCHED_BORE
}
se->vruntime = vruntime - lag;
@@ -6810,6 +7064,14 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
bool was_sched_idle = sched_idle_rq(rq);
util_est_dequeue(&rq->cfs, p);
+#ifdef CONFIG_SCHED_BORE
+ if (task_sleep) {
+ cfs_rq = cfs_rq_of(se);
+ if (cfs_rq->curr == se)
+ update_curr(cfs_rq);
+ restart_burst(se);
+ }
+#endif // CONFIG_SCHED_BORE
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
@@ -8545,16 +8807,25 @@ static void yield_task_fair(struct rq *rq)
/*
* Are we the only task in the tree?
*/
+#if !defined(CONFIG_SCHED_BORE)
if (unlikely(rq->nr_running == 1))
return;
clear_buddies(cfs_rq, se);
+#endif // CONFIG_SCHED_BORE
update_rq_clock(rq);
/*
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
+#ifdef CONFIG_SCHED_BORE
+ restart_burst_rescale_deadline(se);
+ if (unlikely(rq->nr_running == 1))
+ return;
+
+ clear_buddies(cfs_rq, se);
+#endif // CONFIG_SCHED_BORE
/*
* Tell update_rq_clock() that we've just updated,
* so we don't do microscopic update in schedule()
@@ -12644,6 +12915,9 @@ static void task_fork_fair(struct task_struct *p)
curr = cfs_rq->curr;
if (curr)
update_curr(cfs_rq);
+#ifdef CONFIG_SCHED_BORE
+ update_burst_score(se);
+#endif // CONFIG_SCHED_BORE
place_entity(cfs_rq, se, ENQUEUE_INITIAL);
rq_unlock(rq, &rf);
}
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index a3ddf84de..5adea65fa 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -6,7 +6,11 @@
*/
SCHED_FEAT(PLACE_LAG, true)
SCHED_FEAT(PLACE_DEADLINE_INITIAL, true)
+#ifdef CONFIG_SCHED_BORE
+SCHED_FEAT(RUN_TO_PARITY, false)
+#else // !CONFIG_SCHED_BORE
SCHED_FEAT(RUN_TO_PARITY, true)
+#endif // CONFIG_SCHED_BORE
/*
* Prefer to schedule the task we woke last (assuming it failed
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 2e5a95486..fc4ec9ebb 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1929,7 +1929,11 @@ static inline void dirty_sched_domain_sysctl(int cpu)
}
#endif
+#ifdef CONFIG_SCHED_BORE
+extern void sched_update_min_base_slice(void);
+#else // !CONFIG_SCHED_BORE
extern int sched_update_scaling(void);
+#endif // CONFIG_SCHED_BORE
static inline const struct cpumask *task_user_cpus(struct task_struct *p)
{
@@ -2509,6 +2513,9 @@ extern const_debug unsigned int sysctl_sched_nr_migrate;
extern const_debug unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_base_slice;
+#ifdef CONFIG_SCHED_BORE
+extern unsigned int sysctl_sched_min_base_slice;
+#endif // CONFIG_SCHED_BORE
#ifdef CONFIG_SCHED_DEBUG
extern int sysctl_resched_latency_warn_ms;
--
2.43.0.232.ge79552d197
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