Re: [RFC][PATCH] per-uid/gid I/O throttling (was Re: [RFC][PATCH] per-task I/O throttling)

[Andrea Righi <righiandr@users.sourceforge.net>]

Pavel Machek wrote:
> On Tue 2008-01-15 17:49:36, Andrea Righi wrote:
>> Allow to limit the I/O bandwidth for specific uid(s) or gid(s) imposing
>> additional delays on those processes that exceed the limits defined in a
>> configfs tree.
>>
>> Examples:
>>
>> Limit the I/O bandwidth for user www-data (UID 33) to 4MB/s:
>>
>> root@linux:/config/io-throttle# mkdir uid:33
>> root@linux:/config/io-throttle# cd uid:33/
>> root@linux:/config/io-throttle/uid:33# cat io-rate
>>      io-rate: 0 KiB/sec
>>    requested: 0 KiB
>> last_request: 0 jiffies
>>        delta: 388202 jiffies
>> root@linux:/config/io-throttle/uid:33# echo 4096 > io-rate
>> root@linux:/config/io-throttle/uid:33# cat io-rate
>>      io-rate: 4096 KiB/sec
>>    requested: 0 KiB
>> last_request: 389271 jiffies
>>        delta: 91 jiffies
>>
>> Limit the I/O bandwidth of group backup (GID 34) to 512KB/s:
> 
> Maybe ionice from cfq should be improved, instead?

IMHO it would be interesting to have also a way to use the limiting
approach, instead of i/o priority-based only (i.e. checks to ensure that
servicing the requests will not cause the associated user's maximum
quality of service to be exceeded).

see also http://lkml.org/lkml/2008/1/20/157

-Andrea