From mboxrd@z Thu Jan 1 00:00:00 1970 From: compudj@krystal.dyndns.org (Mathieu Desnoyers) Date: Wed, 11 Feb 2009 11:56:48 -0500 Subject: [ltt-dev] [PATCH] LTTng: Make mark-control work in debugfs In-Reply-To: <499299FF.5060403@cn.fujitsu.com> References: <4988F393.8080605@cn.fujitsu.com> <20090204062051.GB10772@Krystal> <49893957.20303@cn.fujitsu.com> <20090204071255.GA12864@Krystal> <498A3EF4.8080602@cn.fujitsu.com> <20090211053221.GD8132@Krystal> <20090211084300.GA14601@Krystal> <499299FF.5060403@cn.fujitsu.com> Message-ID: <20090211165648.GB26549@Krystal> * Gui Jianfeng (guijianfeng at cn.fujitsu.com) wrote: > Mathieu Desnoyers wrote: > > I think I have an idea we could implement to support arming markers > > which are not loaded in the kernel yet. The use-case is : > > > > We have a marker in a given module, which is not loaded. We are > > interested in tracing events in this module happening soon after module > > load. Therefore, we cannot use the /mnt/debugfs/ltt/markers/**/* files, > > because the marker is not present yet. > > > > We could implement mkdir operations to support this. This is out of > > ltt-armall scope, and people would have to use it manually and *know* > > what channel and marker names they want to enable, but I think it's ok. > > > > So basically, we would have : > > > > cd /mnt/debugfs/ltt > > mkdir channel_name > > cd channel_name > > mkdir marker_name > > > > The marker_name subdirectory would be populated with standard > > information and enable files. > > Do you mean if we do "mkdir channel_name" and "mkdir marker_name" > kernel will automatically insert the probe module, but in debugfs, > it doesn't show all of the markers this module have, but just the > requested one? > No. I mean that doing : mkdir channel_name mkdir channel_name/marker_name echo 1 > channel_name/marker_name Should be the same as the echo "connect channel_name marker_name" > /proc/ltt This worked even if the channel/marker pair were not listed in /proc/ltt. This would create the directories locally even if they do not exist in the marker table, and call ltt_marker_connect() when echo 1 > channel_name/marker_name is done. Mathieu > > > > Do you think it could be added easily to ltt-trace-control ? > > > > Mathieu > > > > > >> Thanks, > >> > >> Mathieu > >> > >>>> I'm providing the patch modified to fit with checkpatch below. > >>>> > >>>> Thanks, > >>>> > >>>> Mathieu > >>>> > >>>> > >>>> lttng-make-mark-control-work-in-debugfs > >>>> > >>>> This patch makes mark-control work in debugfs > >>>> Control files are organized as following. > >>>> ltt/ > >>>> |-- markers > >>>> | |-- fs > >>>> | | |-- buffer_wait_end > >>>> | | | |-- enable > >>>> | | | `-- info > >>>> | | |-- buffer_wait_start > >>>> | | | |-- enable > >>>> | | | `-- info > >>>> | | |-- close > >>>> | | | |-- enable > >>>> | | | `-- info > >>>> | | |-- exec > >>>> | | | |-- enable > >>>> | | | `-- info > >>>> ... > >>>> > >>>> One can enable or disable a marker by using the following command > >>>> # echo 1 > ltt/markers/fs/close/enable > >>>> # echo 0 > ltt/markers/fs/close/enable > >>>> > >>>> Show the marker information as following > >>>> # cat ltt/markers/fs/close/info > >>>> format: "fd %u" > >>>> state: 1 > >>>> event_id: 2 > >>>> call: 0xc0459118 > >>>> probe single : 0xc04f7b08 > >>>> > >>>> Mathieu : > >>>> > >>>> enabled -> enable to follow the semantic of the rest of the debugfs API. > >>>> checkpatch.pl cleanup. > >>>> > >>>> Signed-off-by: Gui Jianfeng > >>>> Signed-off-by: Mathieu Desnoyers > >>>> --- > >>>> ltt/ltt-trace-control.c | 298 +++++++++++++++++++++++++++++++++++++++++++++++- > >>>> 1 file changed, 294 insertions(+), 4 deletions(-) > >>>> > >>>> Index: linux-2.6-lttng/ltt/ltt-trace-control.c > >>>> =================================================================== > >>>> --- linux-2.6-lttng.orig/ltt/ltt-trace-control.c 2009-02-04 00:56:05.000000000 -0500 > >>>> +++ linux-2.6-lttng/ltt/ltt-trace-control.c 2009-02-04 01:01:46.000000000 -0500 > >>>> @@ -1,8 +1,10 @@ > >>>> /* > >>>> * LTT trace control module over debugfs. > >>>> * > >>>> - * Copyright 2008 - > >>>> - * Zhaolei > >>>> + * Copyright 2008 - Zhaolei > >>>> + * > >>>> + * Copyright 2009 - Gui Jianfeng > >>>> + * Make mark-control work in debugfs > >>>> */ > >>>> > >>>> /* > >>>> @@ -16,14 +18,17 @@ > >>>> #include > >>>> #include > >>>> #include > >>>> +#include > >>>> > >>>> #define LTT_CONTROL_DIR "control" > >>>> +#define MARKERS_CONTROL_DIR "markers" > >>>> #define LTT_SETUP_TRACE_FILE "setup_trace" > >>>> #define LTT_DESTROY_TRACE_FILE "destroy_trace" > >>>> > >>>> #define LTT_WRITE_MAXLEN (128) > >>>> > >>>> -struct dentry *ltt_control_dir, *ltt_setup_trace_file, *ltt_destroy_trace_file; > >>>> +struct dentry *ltt_control_dir, *ltt_setup_trace_file, *ltt_destroy_trace_file, > >>>> + *markers_control_dir; > >>>> > >>>> /* > >>>> * the traces_lock nests inside control_lock. > >>>> @@ -692,6 +697,270 @@ static struct file_operations ltt_destro > >>>> .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; > >>>> + int err; > >>>> + > >>>> + channel_d = dir_lookup(markers_control_dir, marker->channel); > >>>> + if (!channel_d) { > >>>> + channel_d = debugfs_create_dir(marker->channel, > >>>> + markers_control_dir); > >>>> + if (IS_ERR(channel_d) || !channel_d) { > >>>> + printk(KERN_ERR > >>>> + "%s: build channel dir of %s failed\n", > >>>> + __func__, marker->channel); > >>>> + err = -ENOMEM; > >>>> + goto err_build_fail; > >>>> + } > >>>> + } > >>>> + > >>>> + 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) { > >>>> + printk(KERN_ERR > >>>> + "%s: marker dir of %s failed\n", > >>>> + __func__, marker->name); > >>>> + err = -ENOMEM; > >>>> + goto err_build_fail; > >>>> + } > >>>> + } > >>>> + > >>>> + enable_d = dir_lookup(marker_d, "enable"); > >>>> + if (!enable_d) { > >>>> + enable_d = debugfs_create_file("enable", 0644, marker_d, > >>>> + marker, &enable_fops); > >>>> + if (IS_ERR(enable_d) || !enable_d) { > >>>> + printk(KERN_ERR > >>>> + "%s: create file of %s failed\n", > >>>> + __func__, "enable"); > >>>> + err = -ENOMEM; > >>>> + goto err_build_fail; > >>>> + } > >>>> + } > >>>> + > >>>> + info_d = dir_lookup(marker_d, "info"); > >>>> + if (!info_d) { > >>>> + info_d = debugfs_create_file("info", 0444, marker_d, > >>>> + marker, &info_fops); > >>>> + if (IS_ERR(info_d) || !info_d) { > >>>> + printk(KERN_ERR > >>>> + "%s: create file of %s failed\n", > >>>> + __func__, "enable"); > >>>> + err = -ENOMEM; > >>>> + goto err_build_fail; > >>>> + } > >>>> + } > >>>> + > >>>> + return 0; > >>>> + > >>>> +err_build_fail: > >>>> + return err; > >>>> +} > >>>> + > >>>> +static int build_marker_control_files(void) > >>>> +{ > >>>> + struct marker_iter iter; > >>>> + int err; > >>>> + > >>>> + err = 0; > >>>> + if (!markers_control_dir) > >>>> + return -EEXIST; > >>>> + > >>>> + marker_iter_reset(&iter); > >>>> + marker_iter_start(&iter); > >>>> + for (; iter.marker != NULL; marker_iter_next(&iter)) { > >>>> + err = build_marker_file(iter.marker); > >>>> + if (err) > >>>> + goto err_build_fail; > >>>> + } > >>>> + marker_iter_stop(&iter); > >>>> + return 0; > >>>> + > >>>> +err_build_fail: > >>>> + return err; > >>>> +} > >>>> + > >>>> +static int remove_marker_control_dir(struct marker *marker) > >>>> +{ > >>>> + struct dentry *channel_d, *marker_d; > >>>> + > >>>> + channel_d = dir_lookup(markers_control_dir, marker->channel); > >>>> + if (!channel_d) > >>>> + return -ENOENT; > >>>> + > >>>> + marker_d = dir_lookup(channel_d, marker->name); > >>>> + if (!marker_d) > >>>> + return -ENOENT; > >>>> + > >>>> + debugfs_remove_recursive(marker_d); > >>>> + if (list_empty(&channel_d->d_subdirs)) > >>>> + debugfs_remove(channel_d); > >>>> + > >>>> + return 0; > >>>> +} > >>>> + > >>>> +static void cleanup_control_dir(struct marker *begin, struct marker *end) > >>>> +{ > >>>> + struct marker *iter; > >>>> + > >>>> + if (!markers_control_dir) > >>>> + return; > >>>> + > >>>> + for (iter = begin; iter < end; iter++) > >>>> + remove_marker_control_dir(iter); > >>>> + > >>>> + return; > >>>> +} > >>>> + > >>>> +static void build_control_dir(struct marker *begin, struct marker *end) > >>>> +{ > >>>> + struct marker *iter; > >>>> + int err; > >>>> + > >>>> + err = 0; > >>>> + if (!markers_control_dir) > >>>> + return; > >>>> + > >>>> + for (iter = begin; iter < end; iter++) { > >>>> + err = build_marker_file(iter); > >>>> + if (err) > >>>> + goto err_build_fail; > >>>> + } > >>>> + > >>>> + return; > >>>> +err_build_fail: > >>>> + cleanup_control_dir(begin, end); > >>>> +} > >>>> + > >>>> +static int module_notify(struct notifier_block *self, > >>>> + unsigned long val, void *data) > >>>> +{ > >>>> + struct module *mod = data; > >>>> + > >>>> + switch (val) { > >>>> + case MODULE_STATE_COMING: > >>>> + build_control_dir(mod->markers, > >>>> + mod->markers + mod->num_markers); > >>>> + break; > >>>> + case MODULE_STATE_GOING: > >>>> + cleanup_control_dir(mod->markers, > >>>> + mod->markers + mod->num_markers); > >>>> + break; > >>>> + } > >>>> + return NOTIFY_DONE; > >>>> +} > >>>> + > >>>> +static struct notifier_block module_nb = { > >>>> + .notifier_call = module_notify, > >>>> +}; > >>>> > >>>> static int __init ltt_trace_control_init(void) > >>>> { > >>>> @@ -733,8 +1002,27 @@ static int __init ltt_trace_control_init > >>>> goto err_create_destroy_trace_file; > >>>> } > >>>> > >>>> - return 0; > >>>> + markers_control_dir = debugfs_create_dir(MARKERS_CONTROL_DIR, > >>>> + ltt_root_dentry); > >>>> + if (IS_ERR(markers_control_dir) || !markers_control_dir) { > >>>> + printk(KERN_ERR > >>>> + "ltt_channel_control_init: create dir of %s failed\n", > >>>> + MARKERS_CONTROL_DIR); > >>>> + err = -ENOMEM; > >>>> + goto err_create_marker_control_dir; > >>>> + } > >>>> > >>>> + if (build_marker_control_files()) > >>>> + goto err_build_fail; > >>>> + > >>>> + if (!register_module_notifier(&module_nb)) > >>>> + return 0; > >>>> + > >>>> +err_build_fail: > >>>> + debugfs_remove_recursive(markers_control_dir); > >>>> + markers_control_dir = NULL; > >>>> +err_create_marker_control_dir: > >>>> + debugfs_remove(ltt_destroy_trace_file); > >>>> err_create_destroy_trace_file: > >>>> debugfs_remove(ltt_setup_trace_file); > >>>> err_create_setup_trace_file: > >>>> @@ -759,6 +1047,8 @@ static void __exit ltt_trace_control_exi > >>>> debugfs_remove(ltt_setup_trace_file); > >>>> debugfs_remove(ltt_destroy_trace_file); > >>>> debugfs_remove_recursive(ltt_control_dir); > >>>> + debugfs_remove_recursive(markers_control_dir); > >>>> + unregister_module_notifier(&module_nb); > >>>> } > >>>> > >>>> module_init(ltt_trace_control_init); > >>>> > >>>> > >>> -- > >>> Regards > >>> Gui Jianfeng > >>> > >>> > >>> > >>> _______________________________________________ > >>> 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 > > > > -- > Regards > Gui Jianfeng > > _______________________________________________ > 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