Commit 082ff5a2 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: Change pctrl() behaviour 



Instead of en/dis-abling all counters acting on a particular
task, en/dis- able all counters we created.

[ v2: fix crash on first counter enable ]

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.916937244@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent aa9c67f5

include/linux/init_task.h

+10 −0
Original line number Diff line number Diff line
@@ -108,6 +108,15 @@ extern struct group_info init_groups; 


extern struct cred init_cred;



#ifdef CONFIG_PERF_COUNTERS

# define INIT_PERF_COUNTERS(tsk)					\

	.perf_counter_mutex = 						\

		 __MUTEX_INITIALIZER(tsk.perf_counter_mutex),		\

	.perf_counter_list = LIST_HEAD_INIT(tsk.perf_counter_list),

#else

# define INIT_PERF_COUNTERS(tsk)

#endif



/*

 *  INIT_TASK is used to set up the first task table, touch at

 * your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -171,6 +180,7 @@ extern struct cred init_cred; 
	},								\

	.dirties = INIT_PROP_LOCAL_SINGLE(dirties),			\

	INIT_IDS							\

	INIT_PERF_COUNTERS(tsk)						\

	INIT_TRACE_IRQFLAGS						\

	INIT_LOCKDEP							\

	INIT_FTRACE_GRAPH						\

include/linux/perf_counter.h

+3 −0
Original line number Diff line number Diff line
@@ -469,6 +469,9 @@ struct perf_counter { 
	int				oncpu;

	int				cpu;



	struct list_head		owner_entry;

	struct task_struct		*owner;



	/* mmap bits */

	struct mutex			mmap_mutex;

	atomic_t			mmap_count;

include/linux/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -1389,6 +1389,8 @@ struct task_struct { 
#endif

#ifdef CONFIG_PERF_COUNTERS

	struct perf_counter_context *perf_counter_ctxp;

	struct mutex perf_counter_mutex;

	struct list_head perf_counter_list;

#endif

#ifdef CONFIG_NUMA

	struct mempolicy *mempolicy;

kernel/perf_counter.c

+24 −63
Original line number Diff line number Diff line
@@ -1076,79 +1076,26 @@ static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) 
	__perf_counter_sched_in(ctx, cpuctx, cpu);

}



int perf_counter_task_disable(void)

int perf_counter_task_enable(void)

{

	struct task_struct *curr = current;

	struct perf_counter_context *ctx = curr->perf_counter_ctxp;

	struct perf_counter *counter;

	unsigned long flags;



	if (!ctx || !ctx->nr_counters)

		return 0;



	local_irq_save(flags);



	__perf_counter_task_sched_out(ctx);



	spin_lock(&ctx->lock);



	/*

	 * Disable all the counters:

	 */

	perf_disable();



	list_for_each_entry(counter, &ctx->counter_list, list_entry) {

		if (counter->state != PERF_COUNTER_STATE_ERROR) {

			update_group_times(counter);

			counter->state = PERF_COUNTER_STATE_OFF;

		}

	}



	perf_enable();



	spin_unlock_irqrestore(&ctx->lock, flags);

	mutex_lock(&current->perf_counter_mutex);

	list_for_each_entry(counter, &current->perf_counter_list, owner_entry)

		perf_counter_enable(counter);

	mutex_unlock(&current->perf_counter_mutex);



	return 0;

}



int perf_counter_task_enable(void)

int perf_counter_task_disable(void)

{

	struct task_struct *curr = current;

	struct perf_counter_context *ctx = curr->perf_counter_ctxp;

	struct perf_counter *counter;

	unsigned long flags;

	int cpu;



	if (!ctx || !ctx->nr_counters)

		return 0;



	local_irq_save(flags);

	cpu = smp_processor_id();



	__perf_counter_task_sched_out(ctx);



	spin_lock(&ctx->lock);



	/*

	 * Disable all the counters:

	 */

	perf_disable();



	list_for_each_entry(counter, &ctx->counter_list, list_entry) {

		if (counter->state > PERF_COUNTER_STATE_OFF)

			continue;

		counter->state = PERF_COUNTER_STATE_INACTIVE;

		counter->tstamp_enabled =

			ctx->time - counter->total_time_enabled;

		counter->hw_event.disabled = 0;

	}

	perf_enable();



	spin_unlock(&ctx->lock);



	perf_counter_task_sched_in(curr, cpu);



	local_irq_restore(flags);

	mutex_lock(&current->perf_counter_mutex);

	list_for_each_entry(counter, &current->perf_counter_list, owner_entry)

		perf_counter_disable(counter);

	mutex_unlock(&current->perf_counter_mutex);



	return 0;

}
@@ -1416,6 +1363,11 @@ static int perf_release(struct inode *inode, struct file *file) 
	perf_counter_remove_from_context(counter);

	mutex_unlock(&ctx->mutex);



	mutex_lock(&counter->owner->perf_counter_mutex);

	list_del_init(&counter->owner_entry);

	mutex_unlock(&counter->owner->perf_counter_mutex);

	put_task_struct(counter->owner);



	free_counter(counter);

	put_context(ctx);
@@ -3272,6 +3224,12 @@ SYSCALL_DEFINE5(perf_counter_open, 
	perf_install_in_context(ctx, counter, cpu);

	mutex_unlock(&ctx->mutex);



	counter->owner = current;

	get_task_struct(current);

	mutex_lock(&current->perf_counter_mutex);

	list_add_tail(&counter->owner_entry, &current->perf_counter_list);

	mutex_unlock(&current->perf_counter_mutex);



	fput_light(counter_file, fput_needed2);



out_fput:
@@ -3488,6 +3446,9 @@ void perf_counter_init_task(struct task_struct *child) 


	child->perf_counter_ctxp = NULL;



	mutex_init(&child->perf_counter_mutex);

	INIT_LIST_HEAD(&child->perf_counter_list);



	/*

	 * This is executed from the parent task context, so inherit

	 * counters that have been marked for cloning.