The patch titled
sched: implement staircase deadline scheduler ymf accounting fixes
has been removed from the -mm tree. Its filename was
sched-implement-staircase-deadline-scheduler-ymf-accounting-fixes.patch
This patch was dropped because I need to clear the decks
------------------------------------------------------
Subject: sched: implement staircase deadline scheduler ymf accounting fixes
From: Con Kolivas <kernel@xxxxxxxxxxx>
SMP balancing broke on converting time_slice to usecs.
update_cpu_clock is unnecessarily complex and doesn't allow sub usec values.
Thanks to Willy Tarreau <w@xxxxxx> for picking up SMP idle anomalies.
Signed-off-by: Con Kolivas <kernel@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/sched.c | 42 +++++++++++++++++-------------------------
1 file changed, 17 insertions(+), 25 deletions(-)
diff -puN kernel/sched.c~sched-implement-staircase-deadline-scheduler-ymf-accounting-fixes kernel/sched.c
--- a/kernel/sched.c~sched-implement-staircase-deadline-scheduler-ymf-accounting-fixes
+++ a/kernel/sched.c
@@ -89,12 +89,10 @@ unsigned long long __attribute__((weak))
#define SCHED_PRIO(p) ((p)+MAX_RT_PRIO)
/* Some helpers for converting to/from various scales.*/
-#define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ))
#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
+#define MS_TO_NS(TIME) ((TIME) * 1000000)
#define MS_TO_US(TIME) ((TIME) * 1000)
-/* Can return 0 */
-#define MS_TO_JIFFIES(TIME) ((TIME) * HZ / 1000)
-#define JIFFIES_TO_MS(TIME) ((TIME) * 1000 / HZ)
+#define US_TO_MS(TIME) ((TIME) / 1000)
#define TASK_PREEMPTS_CURR(p, curr) ((p)->prio < (curr)->prio)
@@ -902,29 +900,28 @@ static void requeue_task(struct task_str
/*
* task_timeslice - the total duration a task can run during one major
- * rotation. Returns value in jiffies.
+ * rotation. Returns value in milliseconds as the smallest value can be 1.
*/
-static inline int task_timeslice(struct task_struct *p)
+static int task_timeslice(struct task_struct *p)
{
- int slice;
+ int slice = p->quota; /* quota is in us */
- slice = NS_TO_JIFFIES(p->quota);
if (!rt_task(p))
slice += (PRIO_RANGE - 1 - TASK_USER_PRIO(p)) * slice;
- return slice;
+ return US_TO_MS(slice);
}
/*
* Assume: static_prio_timeslice(NICE_TO_PRIO(0)) == DEF_TIMESLICE
* If static_prio_timeslice() is ever changed to break this assumption then
- * this code will need modification
+ * this code will need modification. Scaled as multiples of milliseconds.
*/
#define TIME_SLICE_NICE_ZERO DEF_TIMESLICE
#define LOAD_WEIGHT(lp) \
(((lp) * SCHED_LOAD_SCALE) / TIME_SLICE_NICE_ZERO)
#define TASK_LOAD_WEIGHT(p) LOAD_WEIGHT(task_timeslice(p))
#define RTPRIO_TO_LOAD_WEIGHT(rp) \
- (LOAD_WEIGHT((MS_TO_JIFFIES(rr_interval) + 20 + (rp))))
+ (LOAD_WEIGHT((rr_interval + 20 + (rp))))
static void set_load_weight(struct task_struct *p)
{
@@ -3263,32 +3260,27 @@ static void
update_cpu_clock(struct task_struct *p, struct rq *rq, unsigned long long now,
int tick)
{
- cputime64_t time_diff = now - p->last_ran;
- const unsigned int min_diff = 1000;
- int us_time_diff;
+ long time_diff = now - p->last_ran;
if (tick) {
/*
* Called from scheduler_tick() there should be less than two
* jiffies worth, and not negative/overflow.
*/
- if (time_diff > JIFFIES_TO_NS(2) || time_diff < min_diff)
+ if (time_diff > JIFFIES_TO_NS(2) || time_diff < 0)
time_diff = JIFFIES_TO_NS(1);
} else {
/*
* Called from context_switch there should be less than one
- * jiffy worth, and not negative/overflowed. In the case when
- * sched_clock fails to return high resolution values this
- * also ensures at least 1 min_diff gets banked.
+ * jiffy worth, and not negative/overflow. There should be
+ * some time banked here so use a nominal 1ms.
*/
- if (time_diff > JIFFIES_TO_NS(1) || time_diff < min_diff)
- time_diff = min_diff;
+ if (time_diff > JIFFIES_TO_NS(1) || time_diff < 1)
+ time_diff = 1000;
}
/* time_slice accounting is done in usecs to avoid overflow on 32bit */
- us_time_diff = time_diff;
- us_time_diff /= 1000;
if (p != rq->idle && p->policy != SCHED_FIFO)
- p->time_slice -= us_time_diff;
+ p->time_slice -= time_diff / 1000;
p->sched_time += time_diff;
p->last_ran = rq->most_recent_timestamp = now;
}
@@ -4868,8 +4860,8 @@ long sys_sched_rr_get_interval(pid_t pid
if (retval)
goto out_unlock;
- jiffies_to_timespec(p->policy == SCHED_FIFO ?
- 0 : task_timeslice(p), &t);
+ t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
+ MS_TO_NS(task_timeslice(p)));
read_unlock(&tasklist_lock);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
out_nounlock:
_
Patches currently in -mm which might be from kernel@xxxxxxxxxxx are
sched-fix-idle-load-balancing-in-softirqd-context-fix.patch
sched-redundant-reschedule-when-set_user_nice-boosts-a-prio-of-a-task-from-the-expired-array.patch
sched-redundant-reschedule-when-set_user_nice-boosts-a-prio-of-a-task-from-the-expired-array-update.patch
sched-implement-staircase-deadline-scheduler-ymf-accounting-fixes.patch
sched-ymf-typo.patch
sched-implement-staircase-deadline-scheduler-load-weight-fix.patch
sched-increase-ksoftirqd-priority.patch
sched-remove-noninteractive-flag.patch
sched-document-sd-cpu-scheduler.patch
sched-implement-staircase-deadline-scheduler-rework-priomatrix-doc.patch
sched-consolidate-sched_clock-drift-adjustments.patch
sched-consolidate-sched_clock-drift-adjustments-fix.patch
sched-implement-staircase-deadline-scheduler-docupdate.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching.patch
swap-prefetch-avoid-repeating-entry.patch
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