Re: Local DoS through write heavy I/O on CFQ & Deadline

Hillf Danton
2012-10-13T13:53:13Z

Hi Alex,

On Sat, Oct 13, 2012 at 12:29 AM, Alex Bligh <alex@alex.org.uk> wrote:
> Michael,
>
> --On 12 October 2012 16:58:39 +0200 Michal Hocko <mhocko@suse.cz> wrote:
>
>> Once dirty_ratio (resp. dirty_bytes) limit is hit then the process which
>> writes gets throttled. If this is not the case then there is a bug in
>> the throttling code.
>
>
> I believe that is the problem.

Take a look at the "wait for writeback" problem please.

Linux 3.0+ Disk performance problem - wrong pdflush behaviour
https://lkml.org/lkml/2012/10/10/412

Hillf