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authorRobert Richter <robert.richter@amd.com>2011-02-11 17:31:44 +0100
committerRobert Richter <robert.richter@amd.com>2011-02-15 11:10:20 +0100
commita0d76247e07abd14968adc4486aaa8e270e9c209 (patch)
treebec9fa0f5a3c7b3d1f3c3032900d74f41941ed2d /arch
parent997dbb4967da248808850c250182ef2528fff2d1 (diff)
downloadlinux-linaro-stable-a0d76247e07abd14968adc4486aaa8e270e9c209.tar.gz
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: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/oprofile/hwsampler_files.c60
-rw-r--r--arch/s390/oprofile/init.c1
2 files changed, 38 insertions, 23 deletions
diff --git a/arch/s390/oprofile/hwsampler_files.c b/arch/s390/oprofile/hwsampler_files.c
index 493f7cc4e861..2e1da2449ba9 100644
--- a/arch/s390/oprofile/hwsampler_files.c
+++ b/arch/s390/oprofile/hwsampler_files.c
@@ -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)
{
+ if (!hwsampler_running) {
+ timer_ops.stop();
+ return;
+ }
+
hwsampler_stop_all();
hwsampler_deallocate();
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;
-}
-
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();
}
diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c
index f6b3f724f590..059b44b9f171 100644
--- a/arch/s390/oprofile/init.c
+++ b/arch/s390/oprofile/init.c
@@ -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);