From f555d61e4d5b19a4b81c8a56e66cafaee0ede45e Mon Sep 17 00:00:00 2001
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Fri, 18 Jan 2013 14:10:12 +0530
Subject: workqueue: Start timer from work

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 workqueue.c | 49 ++++++++++++++++++++++++++-----------------------
 1 file changed, 26 insertions(+), 23 deletions(-)

diff --git a/workqueue.c b/workqueue.c
index b99d768..a92377b 100644
--- a/workqueue.c
+++ b/workqueue.c
@@ -24,6 +24,7 @@
 
 #include <linux/cpumask.h>
 #include <linux/completion.h>
+#include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/percpu.h>
@@ -43,8 +44,6 @@ struct mywork {
 	int cpu;
 } *_myworks;
 
-unsigned int _myworks_index;
-
 struct mytimer {
 	struct timer_list _timer;
 	unsigned int timer_count_left;
@@ -66,13 +65,13 @@ static DEFINE_PER_CPU(struct workqueue_struct *, cpu_wq);
 
 static int total_works_per_timer = 1000, total_works_finished;
 
-#define TIMER_DELAY 10
+#define TIMER_DELAY 5
 static DEFINE_PER_CPU(struct mytimer, _cpu_mytimer);
 DECLARE_COMPLETION(wq_complete);
 
 void timer_fn(unsigned long data)
 {
-	int index, cpu = raw_smp_processor_id();
+	int cpu = raw_smp_processor_id();
 	struct mytimer *_mytimer = (struct mytimer *)data;
 	struct mytimer *cpu_mytimer = &per_cpu(_cpu_mytimer, cpu);
 	struct workqueue_struct **wq = &per_cpu(cpu_wq, cpu);
@@ -83,20 +82,9 @@ void timer_fn(unsigned long data)
 	if (cpu != _mytimer->cpu)
 		cpu_mytimer->timer_migration_count++;
 
-	spin_lock(&tlock);
-	index = _myworks_index++;
-	spin_unlock(&tlock);
-
-	/* queue work and re-arm timer on current cpu */
-	_myworks[index].cpu = cpu;
-	queue_work_on_any_cpu(*wq, &_myworks[index]._work);
+	/* queue work on any cpu */
+	queue_work_on_any_cpu(*wq, &_myworks[_mytimer->cpu]._work);
 	++(*work_queued_count);
-
-	if (--(_mytimer->timer_count_left)) {
-		cpu_mytimer->timer_start_count++;
-		_mytimer->cpu = cpu;
-		mod_timer(&_mytimer->_timer, jiffies + TIMER_DELAY);
-	}
 }
 
 extern int not_idle[5], all_idle[5], non_idle_found[5][5];
@@ -105,10 +93,13 @@ static void wq_function(struct work_struct *_work)
 	int cpu = raw_smp_processor_id(), i;
 	int cpus = num_present_cpus();
 	struct mywork *_mywork = container_of(_work, struct mywork, _work);
+	struct mytimer *_mytimer = &per_cpu(_cpu_mytimer, _mywork->cpu);
 
 	/* Find current cpu id */
 	per_cpu(cpu_work_fn_count, cpu)++;
 
+	mdelay(20);
+
 	/* work is queued and processed by same cpu */
 	if (_mywork->cpu == cpu)
 		per_cpu(cpu_own_work_count, cpu)++;
@@ -145,6 +136,13 @@ static void wq_function(struct work_struct *_work)
 				pr_info("found non idle: src: %d, dest: %d, count: %d\n",
 						cpu, i, non_idle_found[cpu][i]);
 		}
+		return;
+	}
+
+	_mytimer->_timer.expires = jiffies + TIMER_DELAY;
+	if (--(_mytimer->timer_count_left)) {
+		_mytimer->timer_start_count++;
+		add_timer_on(&_mytimer->_timer, _mytimer->cpu);
 	}
 }
 
@@ -165,6 +163,7 @@ static void wq_per_cpu(struct work_struct *_work)
 	_mytimer = &per_cpu(_cpu_mytimer, cpu);
 	timer = &_mytimer->_timer;
 	init_timer(timer);
+	timer->expires = jiffies + TIMER_DELAY;
 	timer->data = (unsigned long)_mytimer;
 	timer->function = timer_fn;
 	_mytimer->timer_count_left = total_works_per_timer;
@@ -172,7 +171,7 @@ static void wq_per_cpu(struct work_struct *_work)
 	_mytimer->timer_fn_count = 0;
 	_mytimer->timer_migration_count = 0;
 	_mytimer->cpu = cpu;
-	mod_timer(timer, jiffies + TIMER_DELAY);
+	add_timer_on(timer, cpu);
 }
 
 static void init_globals(void)
@@ -207,15 +206,17 @@ static int __init wq_module_init(void)
 		return 0;
 	}
 
-	_myworks = kmalloc(cpus * total_works_per_timer * sizeof(*_myworks),
+	_myworks = kmalloc(cpus * sizeof(*_myworks),
 			GFP_KERNEL);
 	if (!_myworks) {
 		pr_err("Failed to allocate work\n");
 		return 0;
 	}
 
-	for (i = 0; i < cpus * total_works_per_timer; i++)
+	for (i = 0; i < cpus; i++) {
 		INIT_WORK(&_myworks[i]._work, wq_function);
+		_myworks[i].cpu = i;
+	}
 
 	init_globals();
 	for_each_present_cpu(cpu) {
@@ -223,7 +224,7 @@ static int __init wq_module_init(void)
 		queue_work_on(cpu, gwq, &gwork[cpu]);
 	}
 
-	wait_for_completion(&wq_complete);
+	wait_for_completion_interruptible(&wq_complete);
 	return 0;
 }
 
@@ -231,14 +232,16 @@ static void __exit wq_module_exit(void)
 {
 	int cpu;
 	struct workqueue_struct *wq;
-
-	kfree(_myworks);
+	struct mytimer *_mytimer;
 
 	for_each_present_cpu(cpu) {
+		_mytimer = &per_cpu(_cpu_mytimer, cpu);
+		del_timer(&_mytimer->_timer);
 		wq = per_cpu(cpu_wq, cpu);
 		destroy_workqueue(wq);
 	}
 
+	kfree(_myworks);
 	kfree(gwork);
 	destroy_workqueue(gwq);
 }
-- 
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