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From 6a203a9662fd9cf0499287f22f26c0a88da35845 Mon Sep 17 00:00:00 2001
From: hamadmarri <hamad.s.almarri@gmail.com>
Date: Fri, 22 Mar 2024 23:48:49 +0300
Subject: [PATCH 4/8] added entity_end_min_slice with min slice = 7us
---
kernel/sched/bs.c | 61 ++++++++++++++++++++++++-----------
kernel/sched/fair_dep_funcs.h | 10 +++---
2 files changed, 46 insertions(+), 25 deletions(-)
diff --git a/kernel/sched/bs.c b/kernel/sched/bs.c
index ea9875792..eaa265715 100644
--- a/kernel/sched/bs.c
+++ b/kernel/sched/bs.c
@@ -14,7 +14,7 @@
#include "sched.h"
#include "pelt.h"
-unsigned int sysctl_sched_base_slice = 750000ULL;
+unsigned int sysctl_sched_base_slice = 7000ULL;
unsigned int bs_shared_quota = 6600000ULL; // 6.6ms
struct lb_env {
@@ -437,31 +437,47 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p)
return true;
}
-static int entity_end_quota(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+static __always_inline
+int __entity_end_quota(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
- unsigned int n = cfs_rq->nr_running;
+ unsigned int n = max(cfs_rq->nr_running, 1);
unsigned int quota;
struct bs_node *bs = &curr->bs_node;
s64 vburst;
- if (n == 0)
- return 1;
+ quota = max(bs_shared_quota / n, sysctl_sched_base_slice);
+ vburst = curr->vruntime - bs->vruntime_start;
+
+ return vburst >= (s64)quota;
+}
- if (n == 1)
+static int entity_end_quota(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+{
+ unsigned int n = cfs_rq->nr_running;
+
+ if (n <= 1)
return 0;
- quota = bs_shared_quota / n;
+ return __entity_end_quota(cfs_rq, curr);
+}
+
+static int entity_end_min_slice(struct sched_entity *curr)
+{
+ struct bs_node *bs = &curr->bs_node;
+ s64 vburst;
+
vburst = curr->vruntime - bs->vruntime_start;
- return vburst >= (s64)quota;
+ return (vburst - (s64)sysctl_sched_base_slice) >= 0;
}
static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int wake_flags)
{
+ struct cfs_rq *cfs_rq = &rq->cfs;
struct task_struct *curr = rq->curr;
- struct sched_entity *se = &curr->se, *pse = &p->se;
+ struct sched_entity *curr_se = &curr->se, *pse = &p->se;
- if (unlikely(se == pse))
+ if (unlikely(curr_se == pse))
return;
if (test_tsk_need_resched(curr))
@@ -479,9 +495,17 @@ static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int
if (unlikely(p->policy != SCHED_NORMAL) || !sched_feat(WAKEUP_PREEMPTION))
return;
- update_curr(cfs_rq_of(se));
+ update_curr(cfs_rq_of(curr_se));
+
+ /*
+ * - if curr_se ended quoat then preempt
+ * - if waked entity is before curr_se and
+ * curr_se ended min slice
+ */
+ if (__entity_end_quota(cfs_rq, curr_se))
+ goto preempt;
- if (entity_before(&pse->bs_node, &se->bs_node))
+ if (entity_before(&pse->bs_node, &curr_se->bs_node) && entity_end_min_slice(curr_se))
goto preempt;
return;
@@ -708,10 +732,9 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
return;
}
- if (cfs_rq->nr_running <= 1)
+ if (cfs_rq->nr_running <= 1) {
clear_rq_candidate(cfs_rq);
-
- if (cfs_rq->nr_running > 1) {
+ } else {
if (curr->yielded || entity_end_quota(cfs_rq, curr)) {
resched_curr(rq_of(cfs_rq));
return;
@@ -721,10 +744,10 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
if (!se)
return;
- if (entity_before(&se->bs_node, &curr->bs_node))
- resched_curr(rq_of(cfs_rq));
-
- return;
+ if (entity_before(&se->bs_node, &curr->bs_node) && entity_end_min_slice(curr)) {
+ resched_curr(rq_of(cfs_rq));
+ return;
+ }
}
/*
diff --git a/kernel/sched/fair_dep_funcs.h b/kernel/sched/fair_dep_funcs.h
index c92c700a7..775c4ec6c 100644
--- a/kernel/sched/fair_dep_funcs.h
+++ b/kernel/sched/fair_dep_funcs.h
@@ -444,16 +444,14 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
return delta;
}
-/*
- * XXX: strictly: vd_i += N*r_i/w_i such that: vd_i > ve_i
- * this is probably good enough.
- */
static void update_deadline(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (cfs_rq->nr_running <= 1)
+ unsigned int n = cfs_rq->nr_running;
+
+ if (n <= 1)
se->slice = bs_shared_quota;
else
- se->slice = bs_shared_quota / cfs_rq->nr_running;
+ se->slice = max(bs_shared_quota / n, sysctl_sched_base_slice);
}
#ifdef CONFIG_SCHED_HRTICK
--
2.44.0
|