lkml.org 
[lkml]   [2013]   [May]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHSET] blk-throttle: implement proper hierarchy support
Hello,

On Thu, May 02, 2013 at 02:45:14PM -0400, Vivek Goyal wrote:
> I did not understand this point. In flat model, application issuing
> at configured page will not get penalized.
>
> This penalty is coming from the fact that we are moving bios after the
> wait and make them wait in another queue.
>
> In flat model there is no such problem. So to me, it is the problem
> of how hierarchical scheduling is implemented. In flat model, I did
> not have to deal with it.

But seen from the parent, the child isn't different from any other
issuer in flat hierarchy. It's just being repeated, so if you assume
a process which behaves in the exact same manner, that process would
get penalized too. e.g. imagine an application which throttles itself
and issues exactly 1MB/s amount of data in direct IO. It'd get
penalized the same way, right?

> Ok. Not having a perfect algorithm now is fine. We can always redo it
> later.

I think we can do source-based RR on bio_lists[] fetching which is
simple enough and should be able to avoid most of the problems, right?

Thanks.

--
tejun


\
 
 \ /
  Last update: 2013-05-03 02:21    [W:0.247 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site