From: Srivatsa Vaddagiri <vatsa@in.ibm.com>
To: Paul Menage <menage@google.com>
Cc: bharata@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
Dhaval Giani <dhaval@linux.vnet.ibm.com>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Gautham R Shenoy <ego@in.ibm.com>, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Pavel Emelyanov <xemul@openvz.org>, Avi Kivity <avi@redhat.com>,
kvm@vger.kernel.org,
Linux Containers <containers@lists.linux-foundation.org>,
Herbert Poetzl <herbert@13thfloor.at>
Subject: Re: [RFC] CPU hard limits
Date: Fri, 5 Jun 2009 17:02:17 +0530 [thread overview]
Message-ID: <20090605113217.GA20786@in.ibm.com> (raw)
In-Reply-To: <6599ad830906050153i1afd104fqe70f681317349142@mail.gmail.com>
On Fri, Jun 05, 2009 at 01:53:15AM -0700, Paul Menage wrote:
> This claim (and the subsequent long thread it generated on how limits
> can provide guarantees) confused me a bit.
>
> Why do we need limits to provide guarantees when we can already
> provide guarantees via shares?
I think the interval over which we need guarantee matters here. Shares
can generally provide guaranteed share of resource over longer (sometimes
minutes) intervals. For high-priority bursty workloads, the latency in
achieving guaranteed resource usage matters. By having hard-limits, we are
"reserving" (potentially idle) slots where the high-priority group can run and
claim its guaranteed share almost immediately.
- vatsa
next prev parent reply other threads:[~2009-06-05 11:32 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-04 5:36 [RFC] CPU hard limits Bharata B Rao
2009-06-04 12:19 ` Avi Kivity
2009-06-04 21:32 ` Mike Waychison
2009-06-05 3:03 ` Bharata B Rao
2009-06-05 3:33 ` Avi Kivity
2009-06-05 4:37 ` Balbir Singh
2009-06-05 4:44 ` Avi Kivity
2009-06-05 4:49 ` Balbir Singh
2009-06-05 5:09 ` Chris Friesen
2009-06-05 5:13 ` Balbir Singh
2009-06-05 5:10 ` Balbir Singh
2009-06-05 5:21 ` Avi Kivity
2009-06-05 5:27 ` Balbir Singh
2009-06-05 5:31 ` Bharata B Rao
2009-06-05 6:01 ` Avi Kivity
2009-06-05 8:16 ` Bharata B Rao
2009-06-07 6:04 ` Avi Kivity
2009-06-07 16:14 ` Bharata B Rao
2009-06-05 9:39 ` Balbir Singh
2009-06-05 13:14 ` Avi Kivity
2009-06-05 13:42 ` Balbir Singh
2009-06-07 6:09 ` Avi Kivity
2009-06-05 14:54 ` Chris Friesen
2009-06-07 6:10 ` Avi Kivity
2009-06-05 9:24 ` Balbir Singh
2009-06-05 6:03 ` Avi Kivity
2009-06-05 6:32 ` Bharata B Rao
2009-06-05 12:57 ` Avi Kivity
2009-06-05 5:16 ` Avi Kivity
2009-06-05 5:20 ` Balbir Singh
2009-06-05 3:07 ` Balbir Singh
2009-06-05 8:53 ` Paul Menage
2009-06-05 9:27 ` Bharata B Rao
2009-06-05 9:32 ` Paul Menage
2009-06-05 9:48 ` Dhaval Giani
2009-06-05 9:51 ` Paul Menage
2009-06-05 9:59 ` Dhaval Giani
2009-06-05 10:03 ` Paul Menage
2009-06-08 8:50 ` Pavel Emelyanov
2009-06-05 9:36 ` Balbir Singh
2009-06-05 9:48 ` Paul Menage
2009-06-05 9:55 ` Balbir Singh
2009-06-05 9:57 ` Paul Menage
2009-06-05 10:02 ` Paul Menage
2009-06-05 11:32 ` Srivatsa Vaddagiri [this message]
2009-06-05 12:18 ` Paul Menage
2009-06-07 10:11 ` Srivatsa Vaddagiri
2009-06-07 15:35 ` Balbir Singh
2009-06-08 4:37 ` Srivatsa Vaddagiri
2009-06-05 14:44 ` Chris Friesen
2009-06-05 13:02 ` Avi Kivity
2009-06-05 13:43 ` Dhaval Giani
2009-06-05 14:45 ` Chris Friesen
2009-06-05 9:02 ` Reinhard Tartler
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