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Message-ID: <20110214190333.GT5874@erda.amd.com>
Date: Mon, 14 Feb 2011 20:03:33 +0100
From: Robert Richter <robert.richter@....com>
To: Heinz Graalfs <graalfs@...ux.vnet.ibm.com>
CC: "mingo@...e.hu" <mingo@...e.hu>,
"oprofile-list@...ts.sf.net" <oprofile-list@...ts.sf.net>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
"borntraeger@...ibm.com" <borntraeger@...ibm.com>,
"schwidefsky@...ibm.com" <schwidefsky@...ibm.com>,
"heiko.carstens@...ibm.com" <heiko.carstens@...ibm.com>,
Mahesh Salgaonkar <mahesh@...ux.vnet.ibm.com>,
Maran Pakkirisamy <maranp@...ux.vnet.ibm.com>
Subject: Re: [patch v2 2/3] This patch enhances OProfile to support System
zs hardware sampling feature
On 14.02.11 20:01:57, Robert Richter wrote:
> I reworked some changes in a follow-on patch which I apply on top of
> your patch set.
See below for the patch.
-Robert
>From c43ad95d99aec85ba497bec3a8a8131a93098281 Mon Sep 17 00:00:00 2001
From: Robert Richter <robert.richter@....com>
Date: Fri, 11 Feb 2011 17:31:44 +0100
Subject: [PATCH] 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(-)
Signed-off-by: Robert Richter <robert.richter@....com>
---
arch/s390/oprofile/hwsampler_files.c | 60 +++++++++++++++++++++------------
arch/s390/oprofile/init.c | 1 -
drivers/oprofile/oprof.c | 32 ------------------
drivers/oprofile/oprof.h | 2 -
drivers/oprofile/timer_int.c | 15 ++-------
include/linux/oprofile.h | 21 ------------
6 files changed, 41 insertions(+), 90 deletions(-)
diff --git a/arch/s390/oprofile/hwsampler_files.c b/arch/s390/oprofile/hwsampler_files.c
index 493f7cc..2e1da24 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 f6b3f72..059b44b 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);
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index 43b01da..f9bda64 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -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;
diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h
index 5a6ceb1..177b73d 100644
--- a/drivers/oprofile/oprof.h
+++ b/drivers/oprofile/oprof.h
@@ -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);
diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index 0099a45..3ef4462 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -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();
-}
diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h
index b517d86..7f5cfd3 100644
--- a/include/linux/oprofile.h
+++ b/include/linux/oprofile.h
@@ -91,27 +91,6 @@ int oprofile_arch_init(struct oprofile_operations * ops);
*/
void oprofile_arch_exit(void);
-#ifdef CONFIG_HAVE_HWSAMPLER
-/**
- * setup hardware sampler for oprofiling.
- */
-
-int oprofile_set_hwsampler(unsigned long);
-
-/**
- * hardware sampler module initialization for the s390 arch
- */
-
-int oprofile_arch_set_hwsampler(struct oprofile_operations *ops);
-
-/**
- * Add an s390 hardware sample.
- */
-void oprofile_add_ext_hw_sample(unsigned long pc, struct pt_regs * const regs,
- unsigned long event, int is_kernel,
- struct task_struct *task);
-#endif /* CONFIG_HAVE_HWSAMPLER */
-
/**
* Add a sample. This may be called from any context.
*/
--
1.7.3.4
--
Advanced Micro Devices, Inc.
Operating System Research Center
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