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Commit 3690b5e6 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Ingo Molnar
Browse files

trace_workqueue: use percpu data for workqueue stat 



Impact: use percpu data instead of a global structure

Use:

   static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);

instead of allocating a global structure.

percpu data also works well on NUMA.

Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ce5e5540

kernel/trace/trace_workqueue.c

+29 −35
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <trace/workqueue.h>

#include <linux/list.h>

#include <linux/percpu.h>

#include "trace_stat.h"

#include "trace.h"
@@ -37,7 +38,8 @@ struct workqueue_global_stats { 
/* Don't need a global lock because allocated before the workqueues, and

 * never freed.

 */

static struct workqueue_global_stats *all_workqueue_stat;

static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);

#define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))



/* Insertion of a work */

static void
@@ -48,8 +50,8 @@ probe_workqueue_insertion(struct task_struct *wq_thread, 
	struct cpu_workqueue_stats *node, *next;

	unsigned long flags;



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	list_for_each_entry_safe(node, next, &all_workqueue_stat[cpu].list,

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	list_for_each_entry_safe(node, next, &workqueue_cpu_stat(cpu)->list,

							list) {

		if (node->pid == wq_thread->pid) {

			atomic_inc(&node->inserted);
@@ -58,7 +60,7 @@ probe_workqueue_insertion(struct task_struct *wq_thread, 
	}

	pr_debug("trace_workqueue: entry not found\n");

found:

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);

}



/* Execution of a work */
@@ -70,8 +72,8 @@ probe_workqueue_execution(struct task_struct *wq_thread, 
	struct cpu_workqueue_stats *node, *next;

	unsigned long flags;



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	list_for_each_entry_safe(node, next, &all_workqueue_stat[cpu].list,

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	list_for_each_entry_safe(node, next, &workqueue_cpu_stat(cpu)->list,

							list) {

		if (node->pid == wq_thread->pid) {

			node->executed++;
@@ -80,7 +82,7 @@ probe_workqueue_execution(struct task_struct *wq_thread, 
	}

	pr_debug("trace_workqueue: entry not found\n");

found:

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);

}



/* Creation of a cpu workqueue thread */
@@ -104,11 +106,11 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu) 


	cws->pid = wq_thread->pid;



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	if (list_empty(&all_workqueue_stat[cpu].list))

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	if (list_empty(&workqueue_cpu_stat(cpu)->list))

		cws->first_entry = true;

	list_add_tail(&cws->list, &all_workqueue_stat[cpu].list);

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	list_add_tail(&cws->list, &workqueue_cpu_stat(cpu)->list);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);

}



/* Destruction of a cpu workqueue thread */
@@ -119,8 +121,8 @@ static void probe_workqueue_destruction(struct task_struct *wq_thread) 
	struct cpu_workqueue_stats *node, *next;

	unsigned long flags;



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	list_for_each_entry_safe(node, next, &all_workqueue_stat[cpu].list,

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	list_for_each_entry_safe(node, next, &workqueue_cpu_stat(cpu)->list,

							list) {

		if (node->pid == wq_thread->pid) {

			list_del(&node->list);
@@ -131,7 +133,7 @@ static void probe_workqueue_destruction(struct task_struct *wq_thread) 


	pr_debug("trace_workqueue: don't find workqueue to destroy\n");

found:

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);



}
@@ -141,13 +143,13 @@ static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu) 
	struct cpu_workqueue_stats *ret = NULL;





	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);



	if (!list_empty(&all_workqueue_stat[cpu].list))

		ret = list_entry(all_workqueue_stat[cpu].list.next,

	if (!list_empty(&workqueue_cpu_stat(cpu)->list))

		ret = list_entry(workqueue_cpu_stat(cpu)->list.next,

				 struct cpu_workqueue_stats, list);



	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);



	return ret;

}
@@ -172,9 +174,9 @@ static void *workqueue_stat_next(void *prev, int idx) 
	unsigned long flags;

	void *ret = NULL;



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	if (list_is_last(&prev_cws->list, &all_workqueue_stat[cpu].list)) {

		spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {

		spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);

		for (++cpu ; cpu < num_possible_cpus(); cpu++) {

			ret = workqueue_stat_start_cpu(cpu);

			if (ret)
@@ -182,7 +184,7 @@ static void *workqueue_stat_next(void *prev, int idx) 
		}

		return NULL;

	}

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);



	return list_entry(prev_cws->list.next, struct cpu_workqueue_stats,

			  list);
@@ -199,10 +201,10 @@ static int workqueue_stat_show(struct seq_file *s, void *p) 
		   cws->executed,

		   trace_find_cmdline(cws->pid));



	spin_lock_irqsave(&all_workqueue_stat[cpu].lock, flags);

	if (&cws->list == all_workqueue_stat[cpu].list.next)

	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);

	if (&cws->list == workqueue_cpu_stat(cpu)->list.next)

		seq_printf(s, "\n");

	spin_unlock_irqrestore(&all_workqueue_stat[cpu].lock, flags);

	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);



	return 0;

}
@@ -258,17 +260,9 @@ int __init trace_workqueue_early_init(void) 
	if (ret)

		goto no_creation;



	all_workqueue_stat = kmalloc(sizeof(struct workqueue_global_stats)

				     * num_possible_cpus(), GFP_KERNEL);



	if (!all_workqueue_stat) {

		pr_warning("trace_workqueue: not enough memory\n");

		goto no_creation;

	}



	for_each_possible_cpu(cpu) {

		spin_lock_init(&all_workqueue_stat[cpu].lock);

		INIT_LIST_HEAD(&all_workqueue_stat[cpu].list);

		spin_lock_init(&workqueue_cpu_stat(cpu)->lock);

		INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);

	}



	return 0;