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authorJason Yeh <jason.yeh@amd.com>2008-07-24 01:05:53 +0400
committerIngo Molnar <mingo@elte.hu>2008-07-26 13:48:16 +0400
commit1a960b402a51d80abf54e3f8e4972374ffe5f22d (patch)
tree108222afe94df145e7a71f44bb077067c35f0131 /drivers/oprofile/oprof.c
parent6852fd9b86d05063c6ef49d2e12e061cc7f6a105 (diff)
downloadlinux-1a960b402a51d80abf54e3f8e4972374ffe5f22d.tar.xz
Oprofile Multiplexing Patch
This patch introduces multiplexing support for the Oprofile kernel module. It basically adds a new function pointer in oprofile_operator allowing each architecture to supply its callback to switch between different sets of event when the timer expires. Userspace tools can modify the time slice through /dev/oprofile/time_slice. It also modifies the number of counters exposed to the userspace through /dev/oprofile. For example, the number of counters for AMD CPUs are changed to 32 and multiplexed in the sets of 4. Signed-off-by: Jason Yeh <jason.yeh@amd.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: oprofile-list <oprofile-list@lists.sourceforge.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r--drivers/oprofile/oprof.c58
1 files changed, 55 insertions, 3 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index 2c645170f06e..b2fa5df64a62 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -12,6 +12,8 @@
#include <linux/init.h>
#include <linux/oprofile.h>
#include <linux/moduleparam.h>
+#include <linux/workqueue.h>
+#include <linux/time.h>
#include <asm/mutex.h>
#include "oprof.h"
@@ -19,13 +21,18 @@
#include "cpu_buffer.h"
#include "buffer_sync.h"
#include "oprofile_stats.h"
+
+static unsigned long is_setup;
+static void switch_worker(struct work_struct *work);
+static DECLARE_DELAYED_WORK(switch_work, switch_worker);
+static DEFINE_MUTEX(start_mutex);
struct oprofile_operations oprofile_ops;
+unsigned long timeout_jiffies;
unsigned long oprofile_started;
unsigned long backtrace_depth;
-static unsigned long is_setup;
-static DEFINE_MUTEX(start_mutex);
+/* Multiplexing defaults at 1 msec*/
/* timer
0 - use performance monitoring hardware if available
@@ -87,6 +94,16 @@ out:
return err;
}
+static void start_switch_worker(void)
+{
+ schedule_delayed_work(&switch_work, timeout_jiffies);
+}
+
+static void switch_worker(struct work_struct *work)
+{
+ if (!oprofile_ops.switch_events())
+ start_switch_worker();
+}
/* Actually start profiling (echo 1>/dev/oprofile/enable) */
int oprofile_start(void)
@@ -94,7 +111,6 @@ int oprofile_start(void)
int err = -EINVAL;
mutex_lock(&start_mutex);
-
if (!is_setup)
goto out;
@@ -108,6 +124,9 @@ int oprofile_start(void)
if ((err = oprofile_ops.start()))
goto out;
+ if (oprofile_ops.switch_events)
+ start_switch_worker();
+
oprofile_started = 1;
out:
mutex_unlock(&start_mutex);
@@ -123,6 +142,7 @@ void oprofile_stop(void)
goto out;
oprofile_ops.stop();
oprofile_started = 0;
+ cancel_delayed_work_sync(&switch_work);
/* wake up the daemon to read what remains */
wake_up_buffer_waiter();
out:
@@ -155,6 +175,32 @@ post_sync:
mutex_unlock(&start_mutex);
}
+/* User inputs in ms, converts to jiffies */
+int oprofile_set_timeout(unsigned long val_msec)
+{
+ int err = 0;
+
+ mutex_lock(&start_mutex);
+
+ if (oprofile_started) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ if (!oprofile_ops.switch_events) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ timeout_jiffies = msecs_to_jiffies(val_msec);
+ if (timeout_jiffies == MAX_JIFFY_OFFSET)
+ timeout_jiffies = msecs_to_jiffies(1);
+
+out:
+ mutex_unlock(&start_mutex);
+ return err;
+
+}
int oprofile_set_backtrace(unsigned long val)
{
@@ -179,10 +225,16 @@ out:
return err;
}
+static void __init oprofile_switch_timer_init(void)
+{
+ timeout_jiffies = msecs_to_jiffies(1);
+}
+
static int __init oprofile_init(void)
{
int err;
+ oprofile_switch_timer_init();
err = oprofile_arch_init(&oprofile_ops);
if (err < 0 || timer) {