interrupts devfs comando linux linux-kernel procfs

linux - comando - devfs



¿Qué significan los contadores en/proc/[pid]/io? (1)

Si bien la página de /proc/[pid]/io está muy atrasada (al igual que la mayoría de las páginas de manual / documentación sobre cualquier cosa que no esté relacionada con el desarrollo del espacio de usuario), afortunadamente esta información está completamente documentada en la fuente del kernel de Linux en Documentation/filesystems/proc.txt . Aquí están los bits relevantes:

rchar ----- I/O counter: chars read The number of bytes which this task has caused to be read from storage. This is simply the sum of bytes which this process passed to read() and pread(). It includes things like tty IO and it is unaffected by whether or not actual physical disk IO was required (the read might have been satisfied from pagecache) wchar ----- I/O counter: chars written The number of bytes which this task has caused, or shall cause to be written to disk. Similar caveats apply here as with rchar. read_bytes ---------- I/O counter: bytes read Attempt to count the number of bytes which this process really did cause to be fetched from the storage layer. Done at the submit_bio() level, so it is accurate for block-backed filesystems. <please add status regarding NFS and CIFS at a later time> write_bytes ----------- I/O counter: bytes written Attempt to count the number of bytes which this process caused to be sent to the storage layer. This is done at page-dirtying time.

Estoy creando un complemento para Munin para monitorear estadísticas de procesos nombrados. Una de las fuentes de información sería /proc/[pid]/io . Pero me cuesta mucho descubrir cuál es la diferencia entre rchar / wchar y read_bytes / written_bytes .

No son lo mismo, ya que proporcionan valores diferentes. ¿Qué representan?