Re: [PATCH 2/4] Memory controller soft limit interface (v3)

[KAMEZAWA Hiroyuki]

On Mon, 2 Mar 2009 11:37:26 +0530
Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:

> * KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2009-03-02 14:35:18]:
> 
> > On Mon, 2 Mar 2009 10:16:31 +0530
> > Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> > 
> > > * KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2009-03-02 11:03:23]:
> > > 
> > > > On Sun, 01 Mar 2009 12:00:11 +0530
> > > > Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> > > > 
> > > > > 
> > > > > From: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
> > > > > 
> > > > > Changelog v2...v1
> > > > > 1. Add support for res_counter_check_soft_limit_locked. This is used
> > > > >    by the hierarchy code.
> > > > > 
> > > > > Add an interface to allow get/set of soft limits. Soft limits for memory plus
> > > > > swap controller (memsw) is currently not supported. Resource counters have
> > > > > been enhanced to support soft limits and new type RES_SOFT_LIMIT has been
> > > > > added. Unlike hard limits, soft limits can be directly set and do not
> > > > > need any reclaim or checks before setting them to a newer value.
> > > > > 
> > > > > Kamezawa-San raised a question as to whether soft limit should belong
> > > > > to res_counter. Since all resources understand the basic concepts of
> > > > > hard and soft limits, it is justified to add soft limits here. Soft limits
> > > > > are a generic resource usage feature, even file system quotas support
> > > > > soft limits.
> > > > > 
> > > > I don't convice adding more logics to res_counter is a good to do, yet.
> > > >
> > > 
> > > Even though it is extensible and you pay the cost only when soft
> > > limits is turned on? Can you show me why you are not convinced?
> > >  
> > Inserting more codes (like "if") to res_counter itself is not welcome..
> > I think res_counter is too complex as counter already.
> >
> 
> Darn.. we better stop all code development!
>  
I don't say such a thing. My point is we have to keep res_counter as light-weight
as possible. If there are alternatives, we should use that.

Thanks,
-Kame



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