Procfs

Overview

The module exposes inside the procfs several informations about every running scheduler thread and worker thread. In particular for every process that opens the UMS device the following tree is created:

/proc/ums/<pid>
├── schedulers
│   ├── ...
│   ├── <scheduler-pid>
│   │   ├── info
│   │   └── workers
│   │       ├── 0 -> /proc/ums/<pid>/workers/<worker-pid>
│   │       ├── ...
│   │       └── n -> /proc/ums/<pid>/workers/<worker-pid>
│   └── ...
└── workers
    ├── ...
    ├── <worker-pid>
    │   └── info
    └── ...

Inside the /proc/ums/<pid>/schedulers there is a folder for each UMS scheduler thread and inside the /proc/ums/<pid>/workers there is a folder for each UMS worker thread.

The info file shows some statistics as the pid of the UMS thread, the number of context switches and the current context state (idle/running).

The /proc/ums/<pid>/schedulers/<scheduler-pid>/workers folder contains a symbolic link for each UMS worker thread the UMS scheduler has dequeued from the completion list; in particular the links are named from 0 to n and they targets the /proc/ums/<pid>/workers/<worker-pid> which they refer to.

Structs

struct ums_proc_dirs

UMS procfs base directories for each process that opens the UMS device

Public Members

char *pid_dir_path: procfs base directory path, i.e. /proc/ums/<pid>

size_t pid_dir_path_size: procfs base directory path length

struct proc_dir_entry *pid_dir: procfs base directory

struct proc_dir_entry *sched_dir: procfs schedulers directory located at /proc/ums/<pid>/schedulers

char *workers_dir_path: procfs workers directory path, i.e. /proc/ums/<pid>/workers

size_t workers_dir_path_size: procfs workers directory path length

struct proc_dir_entry *workers_dir: procfs workers directory

struct ums_scheduler_proc_dirs

UMS scheduler procfs directories

Public Members

struct proc_dir_entry *scheduler_dir: procfs scheduler directory located at /proc/ums/<pid>/schedulers/<sched-pid>

struct proc_dir_entry *scheduler_info_dir: scheduler info file located at /proc/ums/<pid>/schedulers/<sched-pid>/info

struct proc_dir_entry *workers_dir: procfs scheduler’s workers directory located at /proc/ums/<pid>/schedulers/<sched-pid>/workers

unsigned long n_workers: number of UMS workers dequeued from the UMS scheduler’s completion list

unsigned long max_workers

struct ums_worker_complist_node

UMS completion list node with UMS worker

Public Members

struct proc_dir_entry *worker_link: Symbolic link targeting the UMS worker

struct ums_worker_proc_dirs

UMS worker procfs directories

Public Members

char *worker_dir_path: procfs worker directory path, i.e. /proc/ums/<pid>/workers/<worker-pid>

size_t worker_dir_path_size: procfs worker directory path length

struct proc_dir_entry *worker_dir: procfs worker directory

struct proc_dir_entry *worker_info_dir: worker info file located at /proc/ums/<pid>/workers/<worker-pid>/info

struct ums_worker_complist_node complist_node: procfs worker node with a completion list

Functions

int ums_proc_init(void)

Initialize the UMS procfs.

Returns

0 - OK
-ENOMEM - No memory available

void ums_proc_destroy(void): Destroy the UMS procfs.

int ums_proc_dirs_init(struct ums_proc_dirs *dirs)

Initialize the UMS procfs base directories.

Parameters

dirs – [in] pointer to the UMS procfs directories

Returns

0 - OK
-ENOMEM - No memory available

void ums_proc_dirs_destroy(struct ums_proc_dirs *dirs)

Destroy the UMS procfs base directories.

Parameters

dirs – [in] pointer to the UMS procfs directories

const char *get_context_state(struct ums_context *context)

Get a string representation of the UMS context state.

Parameters

context – [in] pointer to the UMS context

Returns

the context state representation

static inline int context_snprintf(char *buf, size_t size, struct ums_context *context)

Get a string representation of the UMS context.

Parameters

buf – [inout] pointer to an allocated buffer
size – [in] maximum number of bytes to write
context – [in] pointer to the UMS context

Returns

the number of characters printed or truncated

int ums_scheduler_proc_register(struct ums_proc_dirs *dirs, struct ums_scheduler *scheduler)

Register the UMS scheduler to the UMS procfs.

Parameters

dirs – [inout] pointer to the UMS procfs directories
scheduler – [in] pointer to the UMS scheduler

Returns

0 - OK
-ENOMEM - No memory available

void ums_scheduler_proc_unregister(struct ums_scheduler *scheduler)

Unregister the UMS scheduler to the UMS procfs.

Parameters

scheduler – [in] pointer to the UMS scheduler

int ums_scheduler_proc_register_worker(struct ums_scheduler_proc_dirs *dirs, struct ums_worker_proc_dirs *worker_dirs)

Register the UMS worker to the UMS scheduler procfs.

Create a symlink inside /proc/ums/<pid>/schedulers/<sched-pid>/workers with the UMS worker as target.

Parameters

dirs – [inout] pointer to the UMS scheduler procfs directories
worker_dirs – [inout] pointer to the UMS worker procfs directories

Returns

0 - OK
-ENOMEM - No memory available

void ums_scheduler_proc_unregister_worker(struct ums_scheduler_proc_dirs *dirs, struct ums_worker_proc_dirs *worker_dirs)

Unregister the UMS worker to the UMS scheduler procfs.

Remove the symlink inside /proc/ums/<pid>/schedulers/<sched-pid>/workers with the UMS worker as target.

Parameters

dirs – [inout] pointer to the UMS scheduler procfs directories
worker_dirs – [inout] pointer to the UMS worker procfs directories

int ums_worker_proc_register(struct ums_proc_dirs *dirs, struct ums_worker *worker)

Register the UMS worker to the UMS procfs.

Parameters

dirs – [inout] pointer to the UMS procfs directories
worker – [in] pointer to the UMS worker

Returns

0 - OK
-ENOMEM - No memory available

void ums_worker_proc_unregister(struct ums_worker *worker)

Unregister the UMS worker to the UMS procfs.

Parameters

worker – [in] pointer to the UMS worker