[PATCH 2/7] cgroup: fix comments
Paul Menage
menage at google.com
Thu Feb 21 17:20:04 PST 2008
On Wed, Feb 20, 2008 at 6:14 PM, Li Zefan <lizf at cn.fujitsu.com> wrote:
> Paul Menage wrote:
> > I think that docbook-style function comments need /** at the start of
> > the comment block.
> >
>
> Yes, I didn't notice it. I revised the patch to fix it.
>
>
> ---
>
>
> fix:
> - comments about need_forkexit_callback
> - comments about release agent
> - typo and comment style, etc.
>
> Signed-off-by: Li Zefan <lizf at cn.fujitsu.com>
Acked-by: Paul Menage <menage at google.com>
> ---
> include/linux/cgroup.h | 2 +-
> kernel/cgroup.c | 142 +++++++++++++++++++++++++++---------------------
> 2 files changed, 80 insertions(+), 64 deletions(-)
>
>
> diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
> index ff9055f..2ebf7af 100644
> --- a/include/linux/cgroup.h
> +++ b/include/linux/cgroup.h
> @@ -175,7 +175,7 @@ struct css_set {
> *
> *
> * When reading/writing to a file:
> - * - the cgroup to use in file->f_dentry->d_parent->d_fsdata
> + * - the cgroup to use is file->f_dentry->d_parent->d_fsdata
> * - the 'cftype' of the file is file->f_dentry->d_fsdata
> */
>
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index 4766bb6..36066d8 100644
>
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -113,9 +113,9 @@ static int root_count;
> #define dummytop (&rootnode.top_cgroup)
>
> /* This flag indicates whether tasks in the fork and exit paths should
> - * take callback_mutex and check for fork/exit handlers to call. This
> - * avoids us having to do extra work in the fork/exit path if none of the
> - * subsystems need to be called.
> + * check for fork/exit handlers to call. This avoids us having to do
> + * extra work in the fork/exit path if none of the subsystems need to
> + * be called.
> */
> static int need_forkexit_callback;
>
> @@ -307,7 +307,6 @@ static inline void put_css_set_taskexit(struct css_set *cg)
> * template: location in which to build the desired set of subsystem
> * state objects for the new cgroup group
> */
> -
> static struct css_set *find_existing_css_set(
> struct css_set *oldcg,
> struct cgroup *cgrp,
> @@ -354,7 +353,6 @@ static struct css_set *find_existing_css_set(
> * and chains them on tmp through their cgrp_link_list fields. Returns 0 on
> * success or a negative error
> */
> -
> static int allocate_cg_links(int count, struct list_head *tmp)
> {
> struct cg_cgroup_link *link;
> @@ -396,7 +394,6 @@ static void free_cg_links(struct list_head *tmp)
> * substituted into the appropriate hierarchy. Must be called with
> * cgroup_mutex held
> */
> -
>
> static struct css_set *find_css_set(
> struct css_set *oldcg, struct cgroup *cgrp)
> {
> @@ -507,8 +504,8 @@ static struct css_set *find_css_set(
>
> * critical pieces of code here. The exception occurs on cgroup_exit(),
> * when a task in a notify_on_release cgroup exits. Then cgroup_mutex
> * is taken, and if the cgroup count is zero, a usermode call made
> - * to /sbin/cgroup_release_agent with the name of the cgroup (path
> - * relative to the root of cgroup file system) as the argument.
> + * to the release agent with the name of the cgroup (path relative to
> + * the root of cgroup file system) as the argument.
> *
> * A cgroup can only be deleted if both its 'count' of using tasks
> * is zero, and its list of 'children' cgroups is empty. Since all
> @@ -521,7 +518,7 @@ static struct css_set *find_css_set(
>
> *
> * The need for this exception arises from the action of
> * cgroup_attach_task(), which overwrites one tasks cgroup pointer with
> - * another. It does so using cgroup_mutexe, however there are
> + * another. It does so using cgroup_mutex, however there are
> * several performance critical places that need to reference
> * task->cgroup without the expense of grabbing a system global
> * mutex. Therefore except as noted below, when dereferencing or, as
> @@ -537,7 +534,6 @@ static struct css_set *find_css_set(
> * cgroup_lock - lock out any changes to cgroup structures
> *
> */
> -
> void cgroup_lock(void)
> {
> mutex_lock(&cgroup_mutex);
> @@ -548,7 +544,6 @@ void cgroup_lock(void)
> *
> * Undo the lock taken in a previous cgroup_lock() call.
> */
> -
> void cgroup_unlock(void)
> {
> mutex_unlock(&cgroup_mutex);
> @@ -590,7 +585,6 @@ static struct inode *cgroup_new_inode(mode_t mode, struct super_block *sb)
> * Call subsys's pre_destroy handler.
> * This is called before css refcnt check.
> */
> -
> static void cgroup_call_pre_destroy(struct cgroup *cgrp)
> {
> struct cgroup_subsys *ss;
> @@ -600,7 +594,6 @@ static void cgroup_call_pre_destroy(struct cgroup *cgrp)
> return;
> }
>
> -
> static void cgroup_diput(struct dentry *dentry, struct inode *inode)
> {
> /* is dentry a directory ? if so, kfree() associated cgroup */
> @@ -1129,8 +1122,13 @@ static inline struct cftype *__d_cft(struct dentry *dentry)
> return dentry->d_fsdata;
> }
>
> -/*
> - * Called with cgroup_mutex held. Writes path of cgroup into buf.
> +/**
> + * cgroup_path - generate the path of a cgroup
> + * @cgrp: the cgroup in question
> + * @buf: the buffer to write the path into
> + * @buflen: the length of the buffer
> + *
> + * Called with cgroup_mutex held. Writes path of cgroup into buf.
> * Returns 0 on success, -errno on error.
> */
> int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
> @@ -1188,11 +1186,13 @@ static void get_first_subsys(const struct cgroup *cgrp,
> *subsys_id = test_ss->subsys_id;
> }
>
> -/*
> - * Attach task 'tsk' to cgroup 'cgrp'
> +/**
> + * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp'
> + * @cgrp: the cgroup the task is attaching to
> + * @tsk: the task to be attached
> *
> - * Call holding cgroup_mutex. May take task_lock of
>
> - * the task 'pid' during call.
> + * Call holding cgroup_mutex. May take task_lock of
>
> + * the task 'tsk' during call.
> */
> int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
> {
> @@ -1293,7 +1293,6 @@ static int attach_task_by_pid(struct cgroup *cgrp, char *pidbuf)
> }
>
> /* The various types of files and directories in a cgroup file system */
> -
> enum cgroup_filetype {
> FILE_ROOT,
> FILE_DIR,
> @@ -1584,12 +1583,11 @@ static int cgroup_create_file(struct dentry *dentry, int mode,
>
> }
>
> /*
> - * cgroup_create_dir - create a directory for an object.
> - * cgrp: the cgroup we create the directory for.
> - * It must have a valid ->parent field
> - * And we are going to fill its ->dentry field.
> - * dentry: dentry of the new cgroup
> - * mode: mode to set on new directory.
> + * cgroup_create_dir - create a directory for an object.
> + * @cgrp: the cgroup we create the directory for. It must have a valid
> + * ->parent field. And we are going to fill its ->dentry field.
> + * @dentry: dentry of the new cgroup
> + * @mode: mode to set on new directory.
> */
> static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry,
> int mode)
> @@ -1651,8 +1649,12 @@ int cgroup_add_files(struct cgroup *cgrp,
> return 0;
> }
>
> -/* Count the number of tasks in a cgroup. */
> -
> +/**
> + * cgroup_task_count - count the number of tasks in a cgroup.
> + * @cgrp: the cgroup in question
> + *
> + * Return the number of tasks in the cgroup.
> + */
> int cgroup_task_count(const struct cgroup *cgrp)
> {
> int count = 0;
> @@ -1962,12 +1964,13 @@ static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
> }
>
> /**
> - * Build and fill cgroupstats so that taskstats can export it to user
> - * space.
> - *
> + * cgroupstats_build - build and fill cgroupstats
> * @stats: cgroupstats to fill information into
> * @dentry: A dentry entry belonging to the cgroup for which stats have
> * been requested.
> + *
> + * Build and fill cgroupstats so that taskstats can export it to user
> + * space.
> */
> int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
> {
> @@ -2199,14 +2202,13 @@ static void init_cgroup_css(struct cgroup_subsys_state *css,
>
> }
>
> /*
> - * cgroup_create - create a cgroup
> - * parent: cgroup that will be parent of the new cgroup.
> - * name: name of the new cgroup. Will be strcpy'ed.
> - * mode: mode to set on new inode
> + * cgroup_create - create a cgroup
> + * @parent: cgroup that will be parent of the new cgroup
> + * @dentry: dentry of the new cgroup
> + * @mode: mode to set on new inode
> *
> - * Must be called with the mutex on the parent inode held
> + * Must be called with the mutex on the parent inode held
> */
> -
> static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
> int mode)
> {
> @@ -2349,13 +2351,12 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
>
> parent = cgrp->parent;
> root = cgrp->root;
> sb = root->sb;
> +
> /*
> - * Call pre_destroy handlers of subsys
> + * Call pre_destroy handlers of subsys. Notify subsystems
> + * that rmdir() request comes.
> */
> cgroup_call_pre_destroy(cgrp);
> - /*
> - * Notify subsyses that rmdir() request comes.
> - */
>
> if (cgroup_has_css_refs(cgrp)) {
> mutex_unlock(&cgroup_mutex);
> @@ -2431,8 +2432,10 @@ static void cgroup_init_subsys(struct cgroup_subsys *ss)
> }
>
> /**
> - * cgroup_init_early - initialize cgroups at system boot, and
> - * initialize any subsystems that request early init.
> + * cgroup_init_early - cgroup initialization at system boot
> + *
> + * Initialize cgroups at system boot, and initialize any
> + * subsystems that request early init.
> */
> int __init cgroup_init_early(void)
> {
> @@ -2474,8 +2477,10 @@ int __init cgroup_init_early(void)
> }
>
> /**
> - * cgroup_init - register cgroup filesystem and /proc file, and
> - * initialize any subsystems that didn't request early init.
> + * cgroup_init - cgroup initialization
> + *
> + * Register cgroup filesystem and /proc file, and initialize
> + * any subsystems that didn't request early init.
> */
> int __init cgroup_init(void)
> {
> @@ -2618,7 +2623,7 @@ static struct file_operations proc_cgroupstats_operations = {
>
>
> /**
> * cgroup_fork - attach newly forked task to its parents cgroup.
> - * @tsk: pointer to task_struct of forking parent process.
> + * @child: pointer to task_struct of forking parent process.
> *
> * Description: A task inherits its parent's cgroup at fork().
> *
> @@ -2642,9 +2647,12 @@ void cgroup_fork(struct task_struct *child)
> }
>
> /**
> - * cgroup_fork_callbacks - called on a new task very soon before
> - * adding it to the tasklist. No need to take any locks since no-one
> - * can be operating on this task
> + * cgroup_fork_callbacks - run fork callbacks
> + * @child: the new task
> + *
> + * Called on a new task very soon before adding it to the
> + * tasklist. No need to take any locks since no-one can
> + * be operating on this task.
> */
> void cgroup_fork_callbacks(struct task_struct *child)
> {
> @@ -2659,11 +2667,14 @@ void cgroup_fork_callbacks(struct task_struct *child)
> }
>
> /**
> - * cgroup_post_fork - called on a new task after adding it to the
> - * task list. Adds the task to the list running through its css_set
> - * if necessary. Has to be after the task is visible on the task list
> - * in case we race with the first call to cgroup_iter_start() - to
> - * guarantee that the new task ends up on its list. */
> + * cgroup_post_fork - called on a new task after adding it to the task list
> + * @child: the task in question
> + *
> + * Adds the task to the list running through its css_set if necessary.
> + * Has to be after the task is visible on the task list in case we race
> + * with the first call to cgroup_iter_start() - to guarantee that the
> + * new task ends up on its list.
> + */
> void cgroup_post_fork(struct task_struct *child)
> {
> if (use_task_css_set_links) {
> @@ -2676,6 +2687,7 @@ void cgroup_post_fork(struct task_struct *child)
> /**
> * cgroup_exit - detach cgroup from exiting task
> * @tsk: pointer to task_struct of exiting process
> + * @run_callback: run exit callbacks?
> *
> * Description: Detach cgroup from @tsk and release it.
> *
> @@ -2706,7 +2718,6 @@ void cgroup_post_fork(struct task_struct *child)
> * top_cgroup isn't going away, and either task has PF_EXITING set,
> * which wards off any cgroup_attach_task() attempts, or task is a failed
> * fork, never visible to cgroup_attach_task.
> - *
> */
> void cgroup_exit(struct task_struct *tsk, int run_callbacks)
> {
> @@ -2743,9 +2754,13 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
> }
>
> /**
> - * cgroup_clone - duplicate the current cgroup in the hierarchy
> - * that the given subsystem is attached to, and move this task into
> - * the new child
> + * cgroup_clone - clone the cgroup the given subsystem is attached to
> + * @tsk: the task to be moved
> + * @subsys: the given subsystem
> + *
> + * Duplicate the current cgroup in the hierarchy that the given
> + * subsystem is attached to, and move this task into the new
> + * child.
> */
> int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
> {
> @@ -2858,9 +2873,12 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
> return ret;
> }
>
> -/*
> - * See if "cgrp" is a descendant of the current task's cgroup in
> - * the appropriate hierarchy
> +/**
> + * cgroup_is_descendant - see if @cgrp is a descendant of current task's cgrp
> + * @cgrp: the cgroup in question
> + *
> + * See if @cgrp is a descendant of the current task's cgroup in
> + * the appropriate hierarchy.
> *
> * If we are sending in dummytop, then presumably we are creating
> * the top cgroup in the subsystem.
> @@ -2939,9 +2957,7 @@ void __css_put(struct cgroup_subsys_state *css)
> * release agent task. We don't bother to wait because the caller of
> * this routine has no use for the exit status of the release agent
> * task, so no sense holding our caller up for that.
> - *
> */
> -
> static void cgroup_release_agent(struct work_struct *work)
> {
> BUG_ON(work != &release_agent_work);
> --
> 1.5.4.rc3
>
>
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