[PATCH 3/5] sched/BT: extend the priority for BT scheduling class
From: xiaoggchen
Date: Fri Jun 21 2019 - 03:55:18 EST
From: chen xiaoguang <xiaoggchen@xxxxxxxxxxx>
The priority of BT scheduler is from 140 to 179.
Signed-off-by: Newton Gao <newtongao@xxxxxxxxxxx>
Signed-off-by: Shook Liu <shookliu@xxxxxxxxxxx>
Signed-off-by: Zhiguang Peng <zgpeng@xxxxxxxxxxx>
Signed-off-by: Xiaoguang Chen <xiaoggchen@xxxxxxxxxxx>
---
include/linux/ioprio.h | 2 +-
include/linux/sched/bt.h | 30 ++++++++++++++++++++++++++++++
include/linux/sched/prio.h | 5 ++++-
init/init_task.c | 6 +++---
kernel/sched/core.c | 15 ++++++++++++---
kernel/sched/cputime.c | 26 ++++++++++++++++++++------
kernel/sched/sched.h | 12 ++++++++++++
7 files changed, 82 insertions(+), 14 deletions(-)
create mode 100644 include/linux/sched/bt.h
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index e9bfe69..3adb9ad 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -62,7 +62,7 @@ static inline int task_nice_ioprio(struct task_struct *task)
*/
static inline int task_nice_ioclass(struct task_struct *task)
{
- if (task->policy == SCHED_IDLE)
+ if (task->policy == SCHED_IDLE || task->policy == SCHED_BT)
return IOPRIO_CLASS_IDLE;
else if (task_is_realtime(task))
return IOPRIO_CLASS_RT;
diff --git a/include/linux/sched/bt.h b/include/linux/sched/bt.h
new file mode 100644
index 0000000..5f40600
--- /dev/null
+++ b/include/linux/sched/bt.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCHED_BT_H
+#define _SCHED_BT_H
+
+/*
+ * SCHED_BT tasks has 140~179 priorities, reflecting
+ * the fact that any of them has slower prio than RT and
+ * NORMAL/BATCH tasks.
+ */
+#define NICE_TO_BT_PRIO(nice) (MAX_RT_PRIO + (nice) + 20 + 40)
+#define PRIO_TO_BT_NICE(prio) ((prio) - MAX_RT_PRIO - 20 - 40)
+static inline int task_bt_nice(const struct task_struct *p)
+{
+ return PRIO_TO_BT_NICE((p)->static_prio);
+}
+
+static inline int bt_prio(int prio)
+{
+ if (unlikely(prio < MAX_PRIO && prio >= MIN_BT_PRIO))
+ return 1;
+ return 0;
+}
+
+static inline int bt_task(struct task_struct *p)
+{
+ return bt_prio(p->prio);
+}
+#endif /* _SCHED_BT_H */
+
+
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index 7d64fea..5c36ed2 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -22,9 +22,12 @@
#define MAX_USER_RT_PRIO 100
#define MAX_RT_PRIO MAX_USER_RT_PRIO
-#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
+#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH + 40)
#define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
+#define MIN_BT_PRIO (MAX_RT_PRIO + 40)
+#define MAX_BT_PRIO (MAX_PRIO - 1)
+
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
diff --git a/init/init_task.c b/init/init_task.c
index c70ef65..603ec4f 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -68,9 +68,9 @@ struct task_struct init_task
.stack = init_stack,
.usage = REFCOUNT_INIT(2),
.flags = PF_KTHREAD,
- .prio = MAX_PRIO - 20,
- .static_prio = MAX_PRIO - 20,
- .normal_prio = MAX_PRIO - 20,
+ .prio = MAX_PRIO - 20 - 40,
+ .static_prio = MAX_PRIO - 20 - 40,
+ .normal_prio = MAX_PRIO - 20 - 40,
.policy = SCHED_NORMAL,
.cpus_allowed = CPU_MASK_ALL,
.nr_cpus_allowed= NR_CPUS,
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3eb4723..b542c17 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2312,7 +2312,8 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
* Revert to default priority/policy on fork if requested.
*/
if (unlikely(p->sched_reset_on_fork)) {
- if (task_has_dl_policy(p) || task_has_rt_policy(p)) {
+ if (task_has_dl_policy(p) || task_has_rt_policy(p) ||
+ task_has_bt_policy(p)) {
p->policy = SCHED_NORMAL;
p->static_prio = NICE_TO_PRIO(0);
p->rt_priority = 0;
@@ -2333,6 +2334,8 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
return -EAGAIN;
else if (rt_prio(p->prio))
p->sched_class = &rt_sched_class;
+ else if (bt_prio(p->prio))
+ p->sched_class = &bt_sched_class;
else
p->sched_class = &fair_sched_class;
@@ -3833,6 +3836,12 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task)
if (oldprio < prio)
queue_flag |= ENQUEUE_HEAD;
p->sched_class = &rt_sched_class;
+ } else if (bt_prio(prio)) {
+ if (dl_prio(oldprio))
+ p->dl.dl_boosted = 0;
+ if (rt_prio(oldprio))
+ p->rt.timeout = 0;
+ p->sched_class = &bt_sched_class;
} else {
if (dl_prio(oldprio))
p->dl.dl_boosted = 0;
@@ -3991,7 +4000,7 @@ int idle_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- if (rq->curr != rq->idle)
+ if (rq->curr != rq->idle && !bt_prio(rq->curr->prio))
return 0;
if (rq->nr_running)
@@ -6200,7 +6209,7 @@ void normalize_rt_tasks(void)
schedstat_set(p->se.statistics.sleep_start, 0);
schedstat_set(p->se.statistics.block_start, 0);
- if (!dl_task(p) && !rt_task(p)) {
+ if (!dl_task(p) && !rt_task(p) && !bt_task(p)) {
/*
* Renice negative nice level userspace
* tasks back to 0:
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 2305ce8..ca26a04 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -122,7 +122,10 @@ void account_user_time(struct task_struct *p, u64 cputime)
p->utime += cputime;
account_group_user_time(p, cputime);
- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
+ if (bt_prio(p->static_prio))
+ index = (task_bt_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
+ else
+ index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
/* Add user time to cpustat. */
task_group_account_field(p, index, cputime);
@@ -146,13 +149,24 @@ void account_guest_time(struct task_struct *p, u64 cputime)
p->gtime += cputime;
/* Add guest time to cpustat. */
- if (task_nice(p) > 0) {
- cpustat[CPUTIME_NICE] += cputime;
- cpustat[CPUTIME_GUEST_NICE] += cputime;
+ if (bt_prio(p->static_prio)) {
+ if (task_bt_nice(p) > 0) {
+ cpustat[CPUTIME_NICE] += cputime;
+ cpustat[CPUTIME_GUEST_NICE] += cputime;
+ } else {
+ cpustat[CPUTIME_USER] += cputime;
+ cpustat[CPUTIME_GUEST] += cputime;
+ }
} else {
- cpustat[CPUTIME_USER] += cputime;
- cpustat[CPUTIME_GUEST] += cputime;
+ if (task_nice(p) > 0) {
+ cpustat[CPUTIME_NICE] += cputime;
+ cpustat[CPUTIME_GUEST_NICE] += cputime;
+ } else {
+ cpustat[CPUTIME_USER] += cputime;
+ cpustat[CPUTIME_GUEST] += cputime;
+ }
}
+
}
/*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 68007be..403eec6 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -32,6 +32,7 @@
#include <linux/sched/user.h>
#include <linux/sched/wake_q.h>
#include <linux/sched/xacct.h>
+#include <linux/sched/bt.h>
#include <uapi/linux/sched/types.h>
@@ -172,6 +173,12 @@ static inline int dl_policy(int policy)
{
return policy == SCHED_DEADLINE;
}
+
+static inline int bt_policy(int policy)
+{
+ return policy == SCHED_BT;
+}
+
static inline bool valid_policy(int policy)
{
return idle_policy(policy) || fair_policy(policy) ||
@@ -193,6 +200,11 @@ static inline int task_has_dl_policy(struct task_struct *p)
return dl_policy(p->policy);
}
+static inline int task_has_bt_policy(struct task_struct *p)
+{
+ return bt_policy(p->policy);
+}
+
#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
/*
--
1.8.3.1