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authorJeremy Fitzhardinge <jeremy@goop.org>2008-08-20 17:02:19 -0700
committerIngo Molnar <mingo@elte.hu>2008-08-21 13:52:58 +0200
commit994025caba3e6beade9bde84dd1b70d9d250f27b (patch)
tree0fe4d6f08d252af1db6a631182725085bb76442b /arch/x86/xen/debugfs.c
parent168d2f464ab9860f0d1e66cf1f9684973222f1c6 (diff)
downloadop-kernel-dev-994025caba3e6beade9bde84dd1b70d9d250f27b.zip
op-kernel-dev-994025caba3e6beade9bde84dd1b70d9d250f27b.tar.gz
xen: add debugfs support
Add support for exporting statistics on mmu updates, multicall batching and pv spinlocks into debugfs. The base path is xen/ and each subsystem adds its own directory: mmu, multicalls, spinlocks. In each directory, writing 1 to "zero_stats" will cause the corresponding stats to be zeroed the next time they're updated. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/xen/debugfs.c')
-rw-r--r--arch/x86/xen/debugfs.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/x86/xen/debugfs.c b/arch/x86/xen/debugfs.c
new file mode 100644
index 0000000..b53225d
--- /dev/null
+++ b/arch/x86/xen/debugfs.c
@@ -0,0 +1,123 @@
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+
+#include "debugfs.h"
+
+static struct dentry *d_xen_debug;
+
+struct dentry * __init xen_init_debugfs(void)
+{
+ if (!d_xen_debug) {
+ d_xen_debug = debugfs_create_dir("xen", NULL);
+
+ if (!d_xen_debug)
+ pr_warning("Could not create 'xen' debugfs directory\n");
+ }
+
+ return d_xen_debug;
+}
+
+struct array_data
+{
+ void *array;
+ unsigned elements;
+};
+
+static int u32_array_open(struct inode *inode, struct file *file)
+{
+ file->private_data = NULL;
+ return nonseekable_open(inode, file);
+}
+
+static size_t format_array(char *buf, size_t bufsize, const char *fmt,
+ u32 *array, unsigned array_size)
+{
+ size_t ret = 0;
+ unsigned i;
+
+ for(i = 0; i < array_size; i++) {
+ size_t len;
+
+ len = snprintf(buf, bufsize, fmt, array[i]);
+ len++; /* ' ' or '\n' */
+ ret += len;
+
+ if (buf) {
+ buf += len;
+ bufsize -= len;
+ buf[-1] = (i == array_size-1) ? '\n' : ' ';
+ }
+ }
+
+ ret++; /* \0 */
+ if (buf)
+ *buf = '\0';
+
+ return ret;
+}
+
+static char *format_array_alloc(const char *fmt, u32 *array, unsigned array_size)
+{
+ size_t len = format_array(NULL, 0, fmt, array, array_size);
+ char *ret;
+
+ ret = kmalloc(len, GFP_KERNEL);
+ if (ret == NULL)
+ return NULL;
+
+ format_array(ret, len, fmt, array, array_size);
+ return ret;
+}
+
+static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
+ loff_t *ppos)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct array_data *data = inode->i_private;
+ size_t size;
+
+ if (*ppos == 0) {
+ if (file->private_data) {
+ kfree(file->private_data);
+ file->private_data = NULL;
+ }
+
+ file->private_data = format_array_alloc("%u", data->array, data->elements);
+ }
+
+ size = 0;
+ if (file->private_data)
+ size = strlen(file->private_data);
+
+ return simple_read_from_buffer(buf, len, ppos, file->private_data, size);
+}
+
+static int xen_array_release(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+
+ return 0;
+}
+
+static struct file_operations u32_array_fops = {
+ .owner = THIS_MODULE,
+ .open = u32_array_open,
+ .release= xen_array_release,
+ .read = u32_array_read,
+};
+
+struct dentry *xen_debugfs_create_u32_array(const char *name, mode_t mode,
+ struct dentry *parent,
+ u32 *array, unsigned elements)
+{
+ struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
+
+ if (data == NULL)
+ return NULL;
+
+ data->array = array;
+ data->elements = elements;
+
+ return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
+}
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