[aio/0] process? - Linux Forums

07-22-2007	#1 (permalink)
corge Just Joined! Join Date: Jul 2007 Posts: 62	[aio/0] process? 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.

07-22-2007	#2 (permalink)
aliov Linux Engineer Join Date: Dec 2006 Location: Geneva,Beirut Posts: 1,079	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. __________________ Linux is not only an operating system, it's a philosophy. My Website.

07-22-2007	#3 (permalink)
devils casper Super Moderator Join Date: Jun 2006 Location: Chandigarh, India Posts: 21,596	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. __________________ It takes a lot of time to be a genius, you have to sit around so much doing nothing, really doing nothing. - Gertrude Stein New Users: Read This First

07-22-2007	#4 (permalink)
corge Just Joined! Join Date: Jul 2007 Posts: 62	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?

07-22-2007

#5 (permalink)

devils casper

Super Moderator

Join Date: Jun 2006

Location: Chandigarh, India

Posts: 21,596

Quote:

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.

Quote:

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)

__________________

It takes a lot of time to be a genius, you have to sit around so much doing nothing, really doing nothing. - Gertrude Stein
New Users: Read This First