Re: [RFC] CPU controllers?

[Nick Piggin <nickpiggin@yahoo.com.au>]

Mike Galbraith wrote:
> On Sat, 2006-06-17 at 23:42 -0700, Andrew Morton wrote:
> 
>>On Sun, 18 Jun 2006 16:11:18 +1000
>>Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
> 
>>>Again, I don't care about the solutions at this stage. I want to know
>>>what the problem is. Please?
>>
>>Isolation.  To prevent one group of processes from damaging the performance
>>of other groups, by providing manageability of the resource consumption of
>>each group.  There are plenty of applications of this, not just
>>server-consolidation-via-server-virtualisation.
> 
> 
> Scheduling contexts do sound useful.  They're easily defeated though, as
> evolution mail demonstrates to me every time it's GUI hangs and I see
> that a nice 19 find is running, eating very little CPU, but effectively
> DoSing evolution nonetheless (journal).  I wonder how often people who
> tried to distribute CPU would likewise be stymied by other resources.

Not entirely infrequently. Which is why it really doesn't seem like
it could be useful from a security point of view without a *huge*
amount of work and complexity... and even from a guaranteed-service
point of view, it still seems (to me) like a pretty big and complex
problem.

As a check box for marketing it sounds pretty cool though, I admit ;)

-- 
SUSE Labs, Novell Inc.
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