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authorJason Yeh <jason.yeh@amd.com>2008-07-23 23:05:53 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-26 11:48:16 +0200
commit1a960b402a51d80abf54e3f8e4972374ffe5f22d (patch)
tree108222afe94df145e7a71f44bb077067c35f0131 /drivers/oprofile/oprofile_files.c
parent6852fd9b86d05063c6ef49d2e12e061cc7f6a105 (diff)
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/oprofile_files.c')
-rw-r--r--drivers/oprofile/oprofile_files.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c
index ef953ba5ab6b..cc4f5a1f8ef2 100644
--- a/drivers/oprofile/oprofile_files.c
+++ b/drivers/oprofile/oprofile_files.c
@@ -9,6 +9,7 @@
#include <linux/fs.h>
#include <linux/oprofile.h>
+#include <linux/jiffies.h>
#include "event_buffer.h"
#include "oprofile_stats.h"
@@ -18,6 +19,40 @@ unsigned long fs_buffer_size = 131072;
unsigned long fs_cpu_buffer_size = 8192;
unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
+static ssize_t timeout_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(jiffies_to_msecs(timeout_jiffies),
+ buf, count, offset);
+}
+
+
+static ssize_t timeout_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+
+ retval = oprofile_set_timeout(val);
+
+ if (retval)
+ return retval;
+ return count;
+}
+
+static const struct file_operations timeout_fops = {
+ .read = timeout_read,
+ .write = timeout_write,
+};
+
+
static ssize_t depth_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
{
return oprofilefs_ulong_to_user(backtrace_depth, buf, count, offset);
@@ -85,11 +120,10 @@ static ssize_t enable_write(struct file * file, char const __user * buf, size_t
if (*offset)
return -EINVAL;
-
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval)
return retval;
-
+
if (val)
retval = oprofile_start();
else
@@ -129,6 +163,7 @@ void oprofile_create_files(struct super_block * sb, struct dentry * root)
oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
+ oprofilefs_create_file(sb, root, "timeout_ms", &timeout_fops);
oprofile_create_stats_files(sb, root);
if (oprofile_ops.create_files)
oprofile_ops.create_files(sb, root);