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Commit a0d76247 authored by Robert Richter's avatar Robert Richter
Browse files

oprofile, s390: Rework hwsampler implementation 



This patch is a rework of the hwsampler oprofile implementation that
has been applied recently. Now there are less non-architectural
changes. The only changes are:

* introduction of oprofile_add_ext_hw_sample(), and
* removal of section attributes of oprofile_timer_init/_exit().

To setup hwsampler for oprofile we need to modify start()/stop()
callbacks and additional hwsampler control files in oprofilefs. We do
not reinitialize the timer or hwsampler mode by restarting calling
init/exit() anymore, instead hwsampler_running is used to switch the
mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
there is also hwsampler_file that reflects the value in oprofilefs.

The overall diffstat of the oprofile s390 hwsampler implemenation
shows the low impact to non-architectural code:

 arch/Kconfig                         |    3 +
 arch/s390/Kconfig                    |    1 +
 arch/s390/oprofile/Makefile          |    2 +-
 arch/s390/oprofile/hwsampler.c       | 1256 ++++++++++++++++++++++++++++++++++
 arch/s390/oprofile/hwsampler.h       |  113 +++
 arch/s390/oprofile/hwsampler_files.c |  162 +++++
 arch/s390/oprofile/init.c            |    6 +-
 drivers/oprofile/cpu_buffer.c        |   24 +-
 drivers/oprofile/timer_int.c         |    4 +-
 include/linux/oprofile.h             |    7 +
 10 files changed, 1567 insertions(+), 11 deletions(-)

Acked-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
parent 997dbb49

arch/s390/oprofile/hwsampler_files.c

+38 −22
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/errno.h>

#include <linux/fs.h>



#include "../../../drivers/oprofile/oprof.h"

#include "hwsampler.h"



#define DEFAULT_INTERVAL	4096
@@ -22,12 +23,20 @@ static unsigned long oprofile_max_interval; 
static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;

static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;



static unsigned long oprofile_hwsampler;

static int hwsampler_file;

static int hwsampler_running;	/* start_mutex must be held to change */



static struct oprofile_operations timer_ops;



static int oprofile_hwsampler_start(void)

{

	int retval;



	hwsampler_running = hwsampler_file;



	if (!hwsampler_running)

		return timer_ops.start();



	retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);

	if (retval)

		return retval;
@@ -41,25 +50,20 @@ static int oprofile_hwsampler_start(void) 


static void oprofile_hwsampler_stop(void)

{

	hwsampler_stop_all();

	hwsampler_deallocate();

	if (!hwsampler_running) {

		timer_ops.stop();

		return;

	}



int oprofile_arch_set_hwsampler(struct oprofile_operations *ops)

{

	printk(KERN_INFO "oprofile: using hardware sampling\n");

	ops->start = oprofile_hwsampler_start;

	ops->stop = oprofile_hwsampler_stop;

	ops->cpu_type = "timer";



	return 0;

	hwsampler_stop_all();

	hwsampler_deallocate();

	return;

}



static ssize_t hwsampler_read(struct file *file, char __user *buf,

		size_t count, loff_t *offset)

{

	return oprofilefs_ulong_to_user(oprofile_hwsampler, buf, count, offset);

	return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);

}



static ssize_t hwsampler_write(struct file *file, char const __user *buf,
@@ -75,15 +79,16 @@ static ssize_t hwsampler_write(struct file *file, char const __user *buf, 
	if (retval)

		return retval;



	if (oprofile_hwsampler == val)

		return -EINVAL;



	retval = oprofile_set_hwsampler(val);

	if (oprofile_started)

		/*

		 * save to do without locking as we set

		 * hwsampler_running in start() when start_mutex is

		 * held

		 */

		return -EBUSY;



	if (retval)

		return retval;

	hwsampler_file = val;



	oprofile_hwsampler = val;

	return count;

}
@@ -98,7 +103,7 @@ static int oprofile_create_hwsampling_files(struct super_block *sb, 
	struct dentry *hw_dir;



	/* reinitialize default values */

	oprofile_hwsampler = 1;

	hwsampler_file = 1;



	hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");

	if (!hw_dir)
@@ -125,7 +130,6 @@ int oprofile_hwsampler_init(struct oprofile_operations* ops) 
	/*

	 * create hwsampler files only if hwsampler_setup() succeeds.

	 */

	ops->create_files = oprofile_create_hwsampling_files;

	oprofile_min_interval = hwsampler_query_min_interval();

	if (oprofile_min_interval < 0) {

		oprofile_min_interval = 0;
@@ -136,11 +140,23 @@ int oprofile_hwsampler_init(struct oprofile_operations* ops) 
		oprofile_max_interval = 0;

		return -ENODEV;

	}

	oprofile_arch_set_hwsampler(ops);



	if (oprofile_timer_init(ops))

		return -ENODEV;



	printk(KERN_INFO "oprofile: using hardware sampling\n");



	memcpy(&timer_ops, ops, sizeof(timer_ops));



	ops->start = oprofile_hwsampler_start;

	ops->stop = oprofile_hwsampler_stop;

	ops->create_files = oprofile_create_hwsampling_files;



	return 0;

}



void oprofile_hwsampler_exit(void)

{

	oprofile_timer_exit();

	hwsampler_shutdown();

}

arch/s390/oprofile/init.c

+0 −1
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <linux/oprofile.h>

#include <linux/init.h>

#include <linux/errno.h>

#include <linux/fs.h>



extern int oprofile_hwsampler_init(struct oprofile_operations* ops);

extern void oprofile_hwsampler_exit(void);

drivers/oprofile/oprof.c

+0 −32
Original line number Diff line number Diff line
@@ -239,38 +239,6 @@ int oprofile_set_ulong(unsigned long *addr, unsigned long val) 
	return err;

}



#ifdef CONFIG_HAVE_HWSAMPLER

int oprofile_set_hwsampler(unsigned long val)

{

	int err = 0;



	mutex_lock(&start_mutex);



	if (oprofile_started) {

		err = -EBUSY;

		goto out;

	}



	switch (val) {

	case 1:

		/* Switch to hardware sampling. */

		__oprofile_timer_exit();

		err = oprofile_arch_set_hwsampler(&oprofile_ops);

		break;

	case 0:

		printk(KERN_INFO "oprofile: using timer interrupt.\n");

		err = __oprofile_timer_init(&oprofile_ops);

		break;

	default:

		err = -EINVAL;

	}



out:

	mutex_unlock(&start_mutex);

	return err;

}

#endif /* CONFIG_HAVE_HWSAMPLER */



static int __init oprofile_init(void)

{

	int err;

drivers/oprofile/oprof.h

+0 −2
Original line number Diff line number Diff line
@@ -35,9 +35,7 @@ struct dentry; 


void oprofile_create_files(struct super_block *sb, struct dentry *root);

int oprofile_timer_init(struct oprofile_operations *ops);

int __oprofile_timer_init(struct oprofile_operations *ops);

void oprofile_timer_exit(void);

void __oprofile_timer_exit(void);



int oprofile_set_ulong(unsigned long *addr, unsigned long val);

int oprofile_set_timeout(unsigned long time);

drivers/oprofile/timer_int.c

+3 −12
Original line number Diff line number Diff line
@@ -97,13 +97,14 @@ static struct notifier_block __refdata oprofile_cpu_notifier = { 
	.notifier_call = oprofile_cpu_notify,

};



int  __oprofile_timer_init(struct oprofile_operations *ops)

int oprofile_timer_init(struct oprofile_operations *ops)

{

	int rc;



	rc = register_hotcpu_notifier(&oprofile_cpu_notifier);

	if (rc)

		return rc;

	ops->create_files = NULL;

	ops->setup = NULL;

	ops->shutdown = NULL;

	ops->start = oprofile_hrtimer_start;
@@ -112,17 +113,7 @@ int __oprofile_timer_init(struct oprofile_operations *ops) 
	return 0;

}



int __init oprofile_timer_init(struct oprofile_operations *ops)

{

	return __oprofile_timer_init(ops);

}



void __oprofile_timer_exit(void)

void oprofile_timer_exit(void)

{

	unregister_hotcpu_notifier(&oprofile_cpu_notifier);

}
 


void __exit oprofile_timer_exit(void)

{

	__oprofile_timer_exit();

}