[aio/0] process?

[corge]

Does anyone know what the "[aio/0]" process is and what its function is?

I have this process running on one of my x86 Slackware 11.0.0 computers. It is not present on my other computers -- also running Slackware 11.0.0.
It uses no CPU and no memory, it seems to be sleeping most of the time and it uses no file descriptors.
I get "Operation not permitted" when I attempt to strace it.

I attempted to look for it using HTTP search engines but found nothing of interest.

[aliov]

I have it also and i didn't manage to kill it, not sure what this is , i didn't find any useful information about it in the web !

but i found it in the kernel source trees, so i suppose it's a kernel function.

/fs/aio.c
./fs/aio.o
./usr/include/linux/aio_abi.h
./arch/um/os-Linux/aio.c
./arch/um/include/aio.h


Hope we can understand it does.
Regards.

[devils casper]

Asynchronous Input/Output ( aio ) is a kernel process and It enables read and write on files opened with O_DIRECT on ext2, ext3, jfs, xfs.

[corge]

Thanks to both of you.
I think I understand why this process only exists on that specific computer -- it is running the 2.6 kernel, whereas my other computers use a 2.4-based kernel.

So this process does asynchronous IO, what does the 2.4-kernel use to handle that? Something which is not visible as a running process per se, perhaps?

[devils casper]

So this process does asynchronous IO, what does the 2.4-kernel use to handle that? Something which is not visible as a running process per se, perhaps?

Kernel 2.4 doesn't support aio. Patches are available for 2.4 kernel but there are a few side effects of those.

This is from mail archive of Suparna Bhattacharya, Linux Technology Centre, IBM Software Labs, India.

1. Motivation

Asynchronous i/o overlaps application processing with i/o operations
for improved utilization of CPU and devices, and improved application
performance, in a dynamic/adaptive manner, especially under high loads
involving large numbers of i/o operations.

1.1 Where aio could be used:

Application performance and scalable connection management:
(a) Communications aio:
Web Servers, Proxy servers, LDAP servers, X-server
(b) Disk/File aio:
Databases, I/O intensive applications
(c) Combination
Streaming content servers (video/audio/web/ftp)
(transfering/serving data/files directly between disk and network)