[ltt-dev] [PATCH] LTTNG: Make marker enabled in advance
Mathieu Desnoyers
compudj at krystal.dyndns.org
Wed Mar 4 12:10:22 EST 2009
* Gui Jianfeng (guijianfeng at cn.fujitsu.com) wrote:
> Hi Mathieu,
>
> This patch makes marker enabled in advance.
> IOW, even if the marker isn't present for the moment,
> you can still enable it for future use.
> As soon as the marker is inserted into kernel, tracing
> work can be started immediately.
>
> Here is an example for using the user interface:
> This patch assumes the marker control patch is applied.
>
> [root at localhost markers]# cd /mnt/debugfs/ltt/markers
> [root at localhost markers]# mkdir fs
> [root at localhost markers]# cd fs
> [root at localhost fs]# mkdir close
> [root at localhost fs]# cd close/
> [root at localhost close]# ls
> enable info
> [root at localhost close]# echo 1 > enable
> [root at localhost close]# cat enable
> 2
> [root at localhost close]# cat info
> marker is not present now!
> [root at localhost close]# modprobe fs_trace
> [root at localhost close]# cat enable
> 1
> [root at localhost close]# cat info
> format: "fd %u"
> state: 1
> event_id: 1
> call: 0xc0468167
> probe single : 0xc0520cdc
>
> Signed-off-by: Gui Jianfeng <guijianfeng at cn.fujitsu.com>
> ---
> ltt/ltt-trace-control.c | 357 ++++++++++++++++++++++++++++++++---------------
> 1 files changed, 247 insertions(+), 110 deletions(-)
>
> diff --git a/ltt/ltt-trace-control.c b/ltt/ltt-trace-control.c
> index 128db4e..7e1c32e 100644
> --- a/ltt/ltt-trace-control.c
> +++ b/ltt/ltt-trace-control.c
> @@ -19,6 +19,7 @@
> #include <linux/debugfs.h>
> #include <linux/ltt-tracer.h>
> #include <linux/notifier.h>
> +#include <linux/mutex.h>
>
> #define LTT_CONTROL_DIR "control"
> #define MARKERS_CONTROL_DIR "markers"
> @@ -27,9 +28,240 @@
>
> #define LTT_WRITE_MAXLEN (128)
>
> +#define MARKER_ENABLE_MASK 0x7UL
What is this doing ?
> +
> +static DEFINE_MUTEX(unload_mutex);
Can you tell me exactly what this protects, where it is nested ?
Mathieu
> +
> struct dentry *ltt_control_dir, *ltt_setup_trace_file, *ltt_destroy_trace_file,
> *markers_control_dir;
>
> +#define get_marker_addr(p) \
> + ((struct marker *)((unsigned long)p & ~MARKER_ENABLE_MASK))
> +#define is_pre_enabled(p) ((unsigned long)p & MARKER_ENABLE_MASK)
> +
> +static int marker_enable_open(struct inode *inode, struct file *filp)
> +{
> + filp->private_data = inode->i_private;
> + return 0;
> +}
> +
> +static ssize_t marker_enable_read(struct file *filp, char __user *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + struct marker *marker;
> + char *buf;
> + int len;
> +
> + marker = get_marker_addr(filp->private_data);
> + buf = kmalloc(1024, GFP_KERNEL);
> +
> + if (marker)
> + len = sprintf(buf, "%d\n", _imv_read(marker->state));
> + else {
> + if (is_pre_enabled(filp->private_data))
> + len = sprintf(buf, "%d\n", 2);
> + else
> + len = sprintf(buf, "%d\n", 0);
> + }
> + len = simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
> + kfree(buf);
> +
> + return len;
> +}
> +
> +static ssize_t marker_enable_write(struct file *filp, const char __user *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + char buf[NAME_MAX];
> + int buf_size;
> + int err = 0;
> + struct marker *marker;
> + const char *channel_name, *marker_name;
> +
> + marker = get_marker_addr(filp->private_data);
> + if (marker) {
> + marker_name = marker->name;
> + channel_name = marker->channel;
> + } else {
> + marker_name = filp->f_dentry->d_parent->d_name.name;
> + channel_name = filp->f_dentry->d_parent->d_parent->d_name.name;
> + filp->f_dentry->d_inode->i_private = (void *)1;
> + }
> +
> + buf_size = min(cnt, sizeof(buf) - 1);
> + err = copy_from_user(buf, ubuf, buf_size);
> + if (err)
> + return err;
> +
> + buf[buf_size] = 0;
> +
> + switch (buf[0]) {
> + case 'Y':
> + case 'y':
> + case '1':
> + err = ltt_marker_connect(channel_name, marker_name,
> + "default");
> + if (err)
> + return err;
> + break;
> + case 'N':
> + case 'n':
> + case '0':
> + err = ltt_marker_disconnect(channel_name,
> + marker_name, "default");
> + if (err)
> + return err;
> + break;
> + default:
> + return -EPERM;
> + }
> +
> + return cnt;
> +}
> +
> +static const struct file_operations enable_fops = {
> + .open = marker_enable_open,
> + .read = marker_enable_read,
> + .write = marker_enable_write,
> +};
> +
> +static int marker_info_open(struct inode *inode, struct file *filp)
> +{
> + filp->private_data = inode->i_private;
> + return 0;
> +}
> +
> +static ssize_t marker_info_read(struct file *filp, char __user *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + struct marker *marker;
> + char *buf;
> + int len;
> +
> + marker = get_marker_addr(filp->private_data);
> + buf = kmalloc(1024, GFP_KERNEL);
> +
> + if (marker)
> + len = sprintf(buf, "format: \"%s\"\nstate: %d\n"
> + "event_id: %hu\n"
> + "call: 0x%p\n"
> + "probe %s : 0x%p\n",
> + marker->format, _imv_read(marker->state),
> + marker->event_id, marker->call, marker->ptype ?
> + "multi" : "single", marker->ptype ?
> + (void *)marker->multi :
> + (void *)marker->single.func);
> + else
> + len = sprintf(buf, "marker is not present now!\n");
> +
> + len = simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
> + kfree(buf);
> +
> + return len;
> +}
> +
> +static const struct file_operations info_fops = {
> + .open = marker_info_open,
> + .read = marker_info_read,
> +};
> +
> +void init_marker_dir(struct dentry *dentry, const struct inode_operations *opt)
> +{
> + dentry->d_inode->i_op = opt;
> +}
> +
> +static int marker_mkdir(struct inode *dir, struct dentry *dentry, int mode)
> +{
> + struct dentry *marker_d, *enable_d, *info_d, *channel_d;
> + int ret;
> +
> + ret = 0;
> + channel_d = (struct dentry *)dir->i_private;
> + mutex_unlock(&dir->i_mutex);
> +
> + /*
> + * Prevent from removing files
> + */
> + mutex_lock(&unload_mutex);
> +
> + marker_d = debugfs_create_dir(dentry->d_name.name,
> + channel_d);
> + if (IS_ERR(marker_d)) {
> + ret = PTR_ERR(marker_d);
> + goto out;
> + }
> +
> + enable_d = debugfs_create_file("enable", 0644, marker_d,
> + NULL, &enable_fops);
> + if (IS_ERR(enable_d) || !enable_d) {
> + printk(KERN_ERR
> + "%s: create file of %s failed\n",
> + __func__, "enable");
> + ret = -ENOMEM;
> + goto remove_marker_dir;
> + }
> +
> + info_d = debugfs_create_file("info", 0644, marker_d,
> + NULL, &info_fops);
> + if (IS_ERR(info_d) || !info_d) {
> + printk(KERN_ERR
> + "%s: create file of %s failed\n",
> + __func__, "info");
> + ret = -ENOMEM;
> + goto remove_enable_dir;
> + }
> +
> + goto out;
> +
> +remove_enable_dir:
> + debugfs_remove(enable_d);
> +remove_marker_dir:
> + debugfs_remove(marker_d);
> +out:
> + mutex_unlock(&unload_mutex);
> + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
> + return ret;
> +}
> +
> +const struct inode_operations channel_dir_opt = {
> + .lookup = simple_lookup,
> + .mkdir = marker_mkdir,
> +};
> +
> +static int channel_mkdir(struct inode *dir, struct dentry *dentry, int mode)
> +{
> + struct dentry *channel_d;
> + int ret;
> +
> + ret = 0;
> + mutex_unlock(&dir->i_mutex);
> +
> + /*
> + * Prevent from removing files
> + */
> + mutex_lock(&unload_mutex);
> +
> + channel_d = debugfs_create_dir(dentry->d_name.name,
> + markers_control_dir);
> + if (IS_ERR(channel_d)) {
> + ret = PTR_ERR(channel_d);
> + goto out;
> + }
> +
> + channel_d->d_inode->i_private = (void *)channel_d;
> + init_marker_dir(channel_d, &channel_dir_opt);
> +
> +out:
> + mutex_unlock(&unload_mutex);
> + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
> + return ret;
> +}
> +
> +const struct inode_operations marker_control_root_dir_opt = {
> + .lookup = simple_lookup,
> + .mkdir = channel_mkdir,
> +};
> +
> /*
> * the traces_lock nests inside control_lock.
> */
> @@ -697,112 +929,6 @@ static struct file_operations ltt_destroy_trace_operations = {
> .write = destroy_trace_write,
> };
>
> -static int marker_enable_open(struct inode *inode, struct file *filp)
> -{
> - filp->private_data = inode->i_private;
> - return 0;
> -}
> -
> -static ssize_t marker_enable_read(struct file *filp, char __user *ubuf,
> - size_t cnt, loff_t *ppos)
> -{
> - struct marker *marker;
> - char *buf;
> - int len;
> -
> - marker = (struct marker *)filp->private_data;
> - buf = kmalloc(1024, GFP_KERNEL);
> -
> - len = sprintf(buf, "%d\n", _imv_read(marker->state));
> -
> - len = simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
> - kfree(buf);
> -
> - return len;
> -}
> -
> -static ssize_t marker_enable_write(struct file *filp, const char __user *ubuf,
> - size_t cnt, loff_t *ppos)
> -{
> - char buf[NAME_MAX];
> - int buf_size;
> - int err = 0;
> - struct marker *marker;
> -
> - marker = (struct marker *)filp->private_data;
> - buf_size = min(cnt, sizeof(buf) - 1);
> - err = copy_from_user(buf, ubuf, buf_size);
> - if (err)
> - return err;
> -
> - buf[buf_size] = 0;
> -
> - switch (buf[0]) {
> - case 'Y':
> - case 'y':
> - case '1':
> - err = ltt_marker_connect(marker->channel, marker->name,
> - "default");
> - if (err)
> - return err;
> - break;
> - case 'N':
> - case 'n':
> - case '0':
> - err = ltt_marker_disconnect(marker->channel, marker->name,
> - "default");
> - if (err)
> - return err;
> - break;
> - default:
> - return -EPERM;
> - }
> -
> - return cnt;
> -}
> -
> -static const struct file_operations enable_fops = {
> - .open = marker_enable_open,
> - .read = marker_enable_read,
> - .write = marker_enable_write,
> -};
> -
> -static int marker_info_open(struct inode *inode, struct file *filp)
> -{
> - filp->private_data = inode->i_private;
> - return 0;
> -}
> -
> -static ssize_t marker_info_read(struct file *filp, char __user *ubuf,
> - size_t cnt, loff_t *ppos)
> -{
> - struct marker *marker;
> - char *buf;
> - int len;
> -
> - marker = (struct marker *)filp->private_data;
> - buf = kmalloc(1024, GFP_KERNEL);
> -
> - len = sprintf(buf, "format: \"%s\"\nstate: %d\n"
> - "event_id: %hu\n"
> - "call: 0x%p\n"
> - "probe %s : 0x%p\n",
> - marker->format, _imv_read(marker->state),
> - marker->event_id, marker->call, marker->ptype ?
> - "multi" : "single", marker->ptype ?
> - (void *)marker->multi : (void *)marker->single.func);
> -
> - len = simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
> - kfree(buf);
> -
> - return len;
> -}
> -
> -static const struct file_operations info_fops = {
> - .open = marker_info_open,
> - .read = marker_info_read,
> -};
> -
> static int build_marker_file(struct marker *marker)
> {
> struct dentry *channel_d, *marker_d, *enable_d, *info_d;
> @@ -820,8 +946,10 @@ static int build_marker_file(struct marker *marker)
> goto err_build_fail;
> }
> }
> + channel_d->d_inode->i_private = (void *)channel_d;
> + init_marker_dir(channel_d, &channel_dir_opt);
>
> - marker_d = dir_lookup(channel_d, marker->name);
> + marker_d = dir_lookup(channel_d, marker->name);
> if (!marker_d) {
> marker_d = debugfs_create_dir(marker->name, channel_d);
> if (IS_ERR(marker_d) || !marker_d) {
> @@ -832,6 +960,7 @@ static int build_marker_file(struct marker *marker)
> goto err_build_fail;
> }
> }
> + marker_d->d_inode->i_private = (void *)marker_d;
>
> enable_d = dir_lookup(marker_d, "enable");
> if (!enable_d) {
> @@ -844,7 +973,8 @@ static int build_marker_file(struct marker *marker)
> err = -ENOMEM;
> goto err_build_fail;
> }
> - }
> + } else
> + enable_d->d_inode->i_private = (void *)marker;
>
> info_d = dir_lookup(marker_d, "info");
> if (!info_d) {
> @@ -857,7 +987,8 @@ static int build_marker_file(struct marker *marker)
> err = -ENOMEM;
> goto err_build_fail;
> }
> - }
> + } else
> + info_d->d_inode->i_private = (void *)marker;
>
> return 0;
>
> @@ -892,6 +1023,7 @@ static int remove_marker_control_dir(struct marker *marker)
> {
> struct dentry *channel_d, *marker_d;
>
> + mutex_lock(&unload_mutex);
> channel_d = dir_lookup(markers_control_dir, marker->channel);
> if (!channel_d)
> return -ENOENT;
> @@ -904,6 +1036,7 @@ static int remove_marker_control_dir(struct marker *marker)
> if (list_empty(&channel_d->d_subdirs))
> debugfs_remove(channel_d);
>
> + mutex_unlock(&unload_mutex);
> return 0;
> }
>
> @@ -1012,6 +1145,8 @@ static int __init ltt_trace_control_init(void)
> goto err_create_marker_control_dir;
> }
>
> + init_marker_dir(markers_control_dir, &marker_control_root_dir_opt);
> +
> if (build_marker_control_files())
> goto err_build_fail;
>
> @@ -1036,6 +1171,7 @@ static void __exit ltt_trace_control_exit(void)
> {
> struct dentry *trace_dir;
>
> + mutex_lock(&unload_mutex);
> /* destory all traces */
> list_for_each_entry(trace_dir, <t_control_dir->d_subdirs,
> d_u.d_child) {
> @@ -1046,9 +1182,10 @@ static void __exit ltt_trace_control_exit(void)
> /* clean dirs in debugfs */
> debugfs_remove(ltt_setup_trace_file);
> debugfs_remove(ltt_destroy_trace_file);
> - debugfs_remove_recursive(ltt_control_dir);
> debugfs_remove_recursive(markers_control_dir);
> + debugfs_remove_recursive(ltt_control_dir);
> unregister_module_notifier(&module_nb);
> + mutex_unlock(&unload_mutex);
> }
>
> module_init(ltt_trace_control_init);
> --
> 1.5.4.rc3
>
>
>
>
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
More information about the lttng-dev
mailing list