Re: Support for SIGSTOP/SIGCONT in nice?

[Simon Josefsson]

Andreas Schwab <address@hidden> writes:

> Simon Josefsson <address@hidden> writes:
>
>> Frequently when I want to run a long-running I/O-bound job (i.e.,
>> rsync of the entire disk to a second disk) on a busy machine (i.e.,
>> mail and web server), the load increases to ~10 from a normal <1.
>
> Assuming you are running on Linux, this is because there are about 10
> processes waiting for disk I/O.
>
>> Using 'nice' doesn't help.  I don't know why this is, but I suspect
>> the kernel scheduler is sub-optimal for disk-bound jobs.
>
> You probably want to change the I/O scheduling class for the process.
> This can be done with ionice (which is Linux specific, included in the
> util-linux package at least on SL 10.1).

Thanks for the hint.  I couldn't find it in Debian, but some googling
revealed:

http://www.kernel.org/pub/linux/utils/util-linux/testing/

ionice is part of the latest pre-releases.  Unfortunately, my kernel
on the system didn't support that syscall so it didn't work.

Regards,
Simon