From: "Martin J. Bligh" <mbligh@aracnet.com>
To: lse-tech <lse-tech@lists.sourceforge.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
Rick Lindsley <ricklind@us.ibm.com>
Subject: breaking down the performance of D7 scheduler patch
Date: Thu, 13 Feb 2003 14:57:52 -0800 [thread overview]
Message-ID: <7790000.1045177072@[10.10.2.4]> (raw)
[-- Attachment #1: Type: text/plain, Size: 8776 bytes --]
Rick broke the non HT parts of D7 out into patches 2,3,4,5 for us.
This has been useful in all sorts of ways ...
http://marc.theaimsgroup.com/?l=lse-tech&m=104436251927067&w=2
(I'll attatch his patches here for convenience, they're small, and I don't
trust the archives not to munge them).
Below I've done two runs on each interesting combo (2 is a no-op).
Overall results are a slight improvement in kernbench and a degredation
in SDET. My impressions from the data below (16x NUMA-Q)
3 - gives a good boost to kernbench, marginal degreadation on SDET.
4 - doesn't do much.
5 - gives some degredation to kernebench, most of the degredation of SDET.
Conclusion: 3 = good (mostly). 5 = bad.
key:
2.5.59 - virgin
2.5.59-sched3 - patch 2 & 3
2.5.59-sched3-2 - patch 2 & 3
2.5.59-sched4 - patch 2 & 3 & 4
2.5.59-sched4-2 - patch 2 & 3 & 4
2.5.59-ricksched - patch 2 & 3 & 4 & 5
2.5.59-ricksched2 - patch 2 & 3 & 4 & 5
Oh, and the runs for 4-2 don't have any schedbench numbers because the
machine crashed, and I'm too lazy to rerun, as it wasn't showing much
anyway.
Kernbench-2: (make -j N vmlinux, where N = 2 x num_cpus)
Elapsed User System CPU
2.5.59 46.08 563.88 118.38 1480.00
2.5.59-sched3 46.12 567.52 115.82 1480.83
2.5.59-sched3-2 46.37 567.81 116.48 1475.00
2.5.59-sched4 46.00 566.28 116.30 1483.17
2.5.59-sched4-2 46.30 567.29 117.43 1478.33
2.5.59-ricksched 46.11 568.54 117.21 1486.67
2.5.59-ricksched2 46.54 568.72 117.43 1473.50
Kernbench-16: (make -j N vmlinux, where N = 16 x num_cpus)
Elapsed User System CPU
2.5.59 47.45 568.02 143.17 1498.17
2.5.59-sched3 47.59 573.48 139.78 1498.33
2.5.59-sched3-2 47.61 573.63 139.97 1498.17
2.5.59-sched4 47.65 573.47 140.47 1497.67
2.5.59-sched4-2 47.73 573.62 141.07 1496.83
2.5.59-ricksched 47.16 571.72 140.02 1508.50
2.5.59-ricksched2 47.19 571.60 138.00 1503.00
DISCLAIMER: SPEC(tm) and the benchmark name SDET(tm) are registered
trademarks of the Standard Performance Evaluation Corporation. This
benchmarking was performed for research purposes only, and the run results
are non-compliant and not-comparable with any published results.
Results are shown as percentages of the first set displayed
SDET 1 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 0.8%
2.5.59-sched3 98.2% 0.8%
2.5.59-sched3-2 97.2% 2.1%
2.5.59-sched4 95.3% 3.5%
2.5.59-sched4-2 97.1% 3.6%
2.5.59-ricksched 89.2% 4.3%
2.5.59-ricksched2 89.4% 2.9%
SDET 2 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 0.6%
2.5.59-sched3 93.3% 7.7%
2.5.59-sched3-2 92.8% 8.5%
2.5.59-sched4 91.0% 10.1%
2.5.59-sched4-2 96.4% 7.4%
2.5.59-ricksched 89.7% 5.6%
2.5.59-ricksched2 84.5% 2.1%
SDET 4 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 5.7%
2.5.59-sched3 96.9% 4.4%
2.5.59-sched3-2 98.6% 5.2%
2.5.59-sched4 102.5% 7.2%
2.5.59-sched4-2 97.0% 1.6%
2.5.59-ricksched 91.4% 3.5%
2.5.59-ricksched2 92.6% 1.5%
SDET 8 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 1.4%
2.5.59-sched3 103.7% 4.8%
2.5.59-sched3-2 102.8% 4.2%
2.5.59-sched4 104.5% 4.3%
2.5.59-sched4-2 102.0% 2.9%
2.5.59-ricksched 102.2% 4.6%
2.5.59-ricksched2 102.5% 1.1%
SDET 16 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 1.7%
2.5.59-sched3 98.9% 1.9%
2.5.59-sched3-2 101.9% 1.8%
2.5.59-sched4 99.1% 1.7%
2.5.59-sched4-2 99.5% 0.9%
2.5.59-ricksched 98.9% 1.1%
2.5.59-ricksched2 78.7% 50.1%
SDET 32 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 1.5%
2.5.59-sched3 98.9% 2.0%
2.5.59-sched3-2 99.7% 0.8%
2.5.59-sched4 97.7% 1.1%
2.5.59-sched4-2 98.7% 1.4%
2.5.59-ricksched 96.7% 1.6%
2.5.59-ricksched2 89.7% 14.9%
SDET 64 (see disclaimer)
Throughput Std. Dev
2.5.59 100.0% 0.7%
2.5.59-sched3 98.8% 0.6%
2.5.59-sched3-2 98.9% 0.4%
2.5.59-sched4 97.8% 0.7%
2.5.59-sched4-2 96.7% 0.9%
2.5.59-ricksched 98.8% 0.7%
2.5.59-ricksched2 97.7% 1.1%
SDET 128 (see disclaimer)
Throughput Std. Dev
NUMA schedbench 4:
AvgUser Elapsed TotalUser TotalSys
2.5.59 0.00 38.88 82.78 0.65
2.5.59-sched3 0.00 30.13 93.10 1.02
2.5.59-sched3-2 0.00 37.47 111.83 0.69
2.5.59-sched4 0.00 30.92 90.07 0.90
2.5.59-sched4-2 0.00 34.20 84.41 0.70
2.5.59-ricksched 0.00 26.40 69.10 0.68
2.5.59-ricksched2 0.00 60.15 170.80 0.98
NUMA schedbench 8:
AvgUser Elapsed TotalUser TotalSys
2.5.59 0.00 49.30 247.80 1.93
2.5.59-sched3 0.00 54.05 306.14 1.50
2.5.59-sched3-2 0.00 39.71 241.97 2.19
2.5.59-sched4 0.00 54.05 305.21 1.35
2.5.59-sched4-2 0 0 0 0
2.5.59-ricksched 0.00 47.32 261.69 1.59
2.5.59-ricksched2 0.00 45.88 260.44 1.70
NUMA schedbench 16:
AvgUser Elapsed TotalUser TotalSys
2.5.59 0.00 57.37 843.12 3.77
2.5.59-sched3 0.00 57.96 849.88 2.81
2.5.59-sched3-2 0.00 57.85 853.58 3.28
2.5.59-sched4 0.00 57.63 847.41 2.78
2.5.59-sched4-2 0 0 0 0
2.5.59-ricksched 0.00 57.48 850.36 3.19
2.5.59-ricksched2 0.00 57.29 848.65 4.21
NUMA schedbench 32:
AvgUser Elapsed TotalUser TotalSys
2.5.59 0.00 116.99 1805.79 6.05
2.5.59-sched3 0.00 120.15 1839.49 6.70
2.5.59-sched3-2 0.00 126.20 1843.77 6.42
2.5.59-sched4 0.00 119.90 1825.33 7.05
2.5.59-sched4-2 0 0 0 0
2.5.59-ricksched 0.00 122.43 1821.62 6.80
2.5.59-ricksched2 0.00 125.44 1821.75 6.96
NUMA schedbench 64:
AvgUser Elapsed TotalUser TotalSys
2.5.59 0.00 235.18 3632.73 15.45
2.5.59-sched3 0.00 238.90 3714.23 17.74
2.5.59-sched3-2 0.00 235.20 3699.45 18.75
2.5.59-sched4 0.00 241.24 3689.19 15.65
2.5.59-sched4-2 0 0 0 0
2.5.59-ricksched 0.00 242.80 3708.15 16.97
2.5.59-ricksched2 0.00 235.71 3693.12 16.50
[-- Attachment #2: 02-struct_change.txt --]
[-- Type: text/plain, Size: 2114 bytes --]
diff -ru linux-2.5.59/include/linux/sched.h sched-2.5.59-02/include/linux/sched.h
--- linux-2.5.59/include/linux/sched.h Thu Jan 16 18:21:38 2003
+++ sched-2.5.59-02/include/linux/sched.h Tue Feb 4 00:30:05 2003
@@ -293,7 +293,7 @@
prio_array_t *array;
unsigned long sleep_avg;
- unsigned long sleep_timestamp;
+ unsigned long last_run;
unsigned long policy;
unsigned long cpus_allowed;
diff -ru linux-2.5.59/kernel/fork.c sched-2.5.59-02/kernel/fork.c
--- linux-2.5.59/kernel/fork.c Thu Jan 16 18:21:38 2003
+++ sched-2.5.59-02/kernel/fork.c Tue Feb 4 00:30:06 2003
@@ -876,7 +876,7 @@
*/
p->first_time_slice = 1;
current->time_slice >>= 1;
- p->sleep_timestamp = jiffies;
+ p->last_run = jiffies;
if (!current->time_slice) {
/*
* This case is rare, it happens when the parent has only
diff -ru linux-2.5.59/kernel/sched.c sched-2.5.59-02/kernel/sched.c
--- linux-2.5.59/kernel/sched.c Thu Jan 16 18:22:29 2003
+++ sched-2.5.59-02/kernel/sched.c Tue Feb 4 00:30:05 2003
@@ -324,14 +324,14 @@
*/
static inline void activate_task(task_t *p, runqueue_t *rq)
{
- unsigned long sleep_time = jiffies - p->sleep_timestamp;
+ unsigned long sleep_time = jiffies - p->last_run;
prio_array_t *array = rq->active;
if (!rt_task(p) && sleep_time) {
/*
* This code gives a bonus to interactive tasks. We update
* an 'average sleep time' value here, based on
- * sleep_timestamp. The more time a task spends sleeping,
+ * ->last_run. The more time a task spends sleeping,
* the higher the average gets - and the higher the priority
* boost gets as well.
*/
@@ -975,7 +975,7 @@
*/
#define CAN_MIGRATE_TASK(p,rq,this_cpu) \
- ((jiffies - (p)->sleep_timestamp > cache_decay_ticks) && \
+ ((jiffies - (p)->last_run > cache_decay_ticks) && \
!task_running(rq, p) && \
((p)->cpus_allowed & (1UL << (this_cpu))))
@@ -1160,7 +1160,7 @@
rq = this_rq();
release_kernel_lock(prev);
- prev->sleep_timestamp = jiffies;
+ prev->last_run = jiffies;
spin_lock_irq(&rq->lock);
/*
[-- Attachment #3: 03-tunables.txt --]
[-- Type: text/plain, Size: 1487 bytes --]
diff -ru sched-2.5.59-02/kernel/sched.c sched-2.5.59-03/kernel/sched.c
--- sched-2.5.59-02/kernel/sched.c Tue Feb 4 00:30:05 2003
+++ sched-2.5.59-03/kernel/sched.c Tue Feb 4 00:31:43 2003
@@ -54,20 +54,19 @@
/*
* These are the 'tuning knobs' of the scheduler:
*
- * Minimum timeslice is 10 msecs, default timeslice is 150 msecs,
- * maximum timeslice is 300 msecs. Timeslices get refilled after
+ * Minimum timeslice is 10 msecs, default timeslice is 100 msecs,
+ * maximum timeslice is 200 msecs. Timeslices get refilled after
* they expire.
*/
#define MIN_TIMESLICE ( 10 * HZ / 1000)
-#define MAX_TIMESLICE (300 * HZ / 1000)
-#define CHILD_PENALTY 95
+#define MAX_TIMESLICE (200 * HZ / 1000)
+#define CHILD_PENALTY 50
#define PARENT_PENALTY 100
#define EXIT_WEIGHT 3
#define PRIO_BONUS_RATIO 25
#define INTERACTIVE_DELTA 2
-#define MAX_SLEEP_AVG (2*HZ)
-#define STARVATION_LIMIT (2*HZ)
-#define NODE_THRESHOLD 125
+#define MAX_SLEEP_AVG (10*HZ)
+#define STARVATION_LIMIT (30*HZ)
/*
* If a task is 'interactive' then we reinsert it in the active
@@ -1035,9 +1034,9 @@
* increasing number of running tasks:
*/
#define EXPIRED_STARVING(rq) \
- ((rq)->expired_timestamp && \
+ (STARVATION_LIMIT && ((rq)->expired_timestamp && \
(jiffies - (rq)->expired_timestamp >= \
- STARVATION_LIMIT * ((rq)->nr_running) + 1))
+ STARVATION_LIMIT * ((rq)->nr_running) + 1)))
/*
* This function gets called by the timer code, with HZ frequency.
[-- Attachment #4: 04-oldmm.txt --]
[-- Type: text/plain, Size: 1499 bytes --]
diff -ru sched-2.5.59-03/kernel/sched.c sched-2.5.59-04/kernel/sched.c
--- sched-2.5.59-03/kernel/sched.c Tue Feb 4 00:31:43 2003
+++ sched-2.5.59-04/kernel/sched.c Tue Feb 4 00:40:20 2003
@@ -151,6 +151,7 @@
unsigned long nr_running, nr_switches, expired_timestamp,
nr_uninterruptible;
task_t *curr, *idle;
+ struct mm_struct *prev_mm;
prio_array_t *active, *expired, arrays[2];
int prev_nr_running[NR_CPUS];
#ifdef CONFIG_NUMA
@@ -560,7 +561,7 @@
* context_switch - switch to the new MM and the new
* thread's register state.
*/
-static inline task_t * context_switch(task_t *prev, task_t *next)
+static inline task_t * context_switch(runqueue_t *rq, task_t *prev, task_t *next)
{
struct mm_struct *mm = next->mm;
struct mm_struct *oldmm = prev->active_mm;
@@ -574,7 +575,7 @@
if (unlikely(!prev->mm)) {
prev->active_mm = NULL;
- mmdrop(oldmm);
+ rq->prev_mm = oldmm;
}
/* Here we just switch the register state and the stack. */
@@ -1213,14 +1214,19 @@
RCU_qsctr(prev->thread_info->cpu)++;
if (likely(prev != next)) {
+ struct mm_struct *prev_mm;
rq->nr_switches++;
rq->curr = next;
prepare_arch_switch(rq, next);
- prev = context_switch(prev, next);
+ prev = context_switch(rq, prev, next);
barrier();
rq = this_rq();
+ prev_mm = rq->prev_mm;
+ rq->prev_mm = NULL;
finish_arch_switch(rq, prev);
+ if (prev_mm)
+ mmdrop(prev_mm);
} else
spin_unlock_irq(&rq->lock);
[-- Attachment #5: 05-activate_task.txt --]
[-- Type: text/plain, Size: 3510 bytes --]
diff -ru sched-2.5.59-04/kernel/sched.c sched-2.5.59-05/kernel/sched.c
--- sched-2.5.59-04/kernel/sched.c Tue Feb 4 00:40:20 2003
+++ sched-2.5.59-05/kernel/sched.c Tue Feb 4 02:24:21 2003
@@ -67,6 +67,8 @@
#define INTERACTIVE_DELTA 2
#define MAX_SLEEP_AVG (10*HZ)
#define STARVATION_LIMIT (30*HZ)
+#define SYNC_WAKEUPS 1
+#define SMART_WAKE_CHILD 1
/*
* If a task is 'interactive' then we reinsert it in the active
@@ -322,6 +324,13 @@
* Also update all the scheduling statistics stuff. (sleep average
* calculation, priority modifiers, etc.)
*/
+static inline void __activate_task(task_t *p, runqueue_t *rq)
+{
+ enqueue_task(p, rq->active);
+ nr_running_inc(rq);
+}
+
+
static inline void activate_task(task_t *p, runqueue_t *rq)
{
unsigned long sleep_time = jiffies - p->last_run;
@@ -340,8 +349,7 @@
p->sleep_avg = MAX_SLEEP_AVG;
p->prio = effective_prio(p);
}
- enqueue_task(p, array);
- nr_running_inc(rq);
+ __activate_task(p, rq);
}
/*
@@ -455,6 +463,7 @@
long old_state;
runqueue_t *rq;
+ sync &= SYNC_WAKEUPS;
repeat_lock_task:
rq = task_rq_lock(p, &flags);
old_state = p->state;
@@ -473,10 +482,13 @@
}
if (old_state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
- activate_task(p, rq);
-
- if (p->prio < rq->curr->prio)
- resched_task(rq->curr);
+ if (sync)
+ __activate_task(p, rq);
+ else {
+ activate_task(p, rq);
+ if (p->prio < rq->curr->prio)
+ resched_task(rq->curr);
+ }
success = 1;
}
p->state = TASK_RUNNING;
@@ -512,8 +524,19 @@
p->prio = effective_prio(p);
}
set_task_cpu(p, smp_processor_id());
- activate_task(p, rq);
+ if (SMART_WAKE_CHILD) {
+ if (unlikely(!current->array))
+ __activate_task(p, rq);
+ else {
+ p->prio = current->prio;
+ list_add_tail(&p->run_list, ¤t->run_list);
+ p->array = current->array;
+ p->array->nr_active++;
+ nr_running_inc(rq);
+ }
+ } else
+ activate_task(p, rq);
rq_unlock(rq);
}
@@ -790,7 +813,23 @@
#endif /* CONFIG_NUMA */
-#if CONFIG_SMP
+/*
+ * One of the idle_cpu_tick() and busy_cpu_tick() functions will
+ * get called every timer tick, on every CPU. Our balancing action
+ * frequency and balancing agressivity depends on whether the CPU is
+ * idle or not.
+ *
+ * busy-rebalance every 250 msecs. idle-rebalance every 1 msec. (or on
+ * systems with HZ=100, every 10 msecs.)
+ */
+#define BUSY_REBALANCE_TICK (HZ/4 ?: 1)
+#define IDLE_REBALANCE_TICK (HZ/1000 ?: 1)
+
+#if !CONFIG_SMP
+
+static inline void load_balance(runqueue_t *rq, int this_cpu, int idle) { }
+
+#else
/*
* double_lock_balance - lock the busiest runqueue
@@ -972,6 +1011,9 @@
* 1) running (obviously), or
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
+ *
+ * (except if we are in idle mode which is a more agressive
+ * form of rebalancing.)
*/
#define CAN_MIGRATE_TASK(p,rq,this_cpu) \
@@ -1665,7 +1707,7 @@
else
p->prio = p->static_prio;
if (array)
- activate_task(p, task_rq(p));
+ __activate_task(p, task_rq(p));
out_unlock:
task_rq_unlock(rq, &flags);
@@ -2297,7 +2339,7 @@
set_task_cpu(p, cpu_dest);
if (p->array) {
deactivate_task(p, rq_src);
- activate_task(p, rq_dest);
+ __activate_task(p, rq_dest);
if (p->prio < rq_dest->curr->prio)
resched_task(rq_dest->curr);
}
next reply other threads:[~2003-02-13 22:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-02-13 22:57 Martin J. Bligh [this message]
2003-02-14 16:04 ` Martin J. Bligh
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