From: "Chris Friesen" <cfriesen@nortel.com>
To: vatsa@in.ibm.com
Cc: Paul Menage <menage@google.com>,
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, 05 Jun 2009 08:44:15 -0600 [thread overview]
Message-ID: <4A292F3F.8010402@nortel.com> (raw)
In-Reply-To: <20090605113217.GA20786@in.ibm.com>
Srivatsa Vaddagiri wrote:
> 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.
Why do you need to "reserve" it though? By definition, if it's
high-priority then it should be able to interrupt the currently running
task.
Chris
next prev parent reply other threads:[~2009-06-05 14:44 UTC|newest]
Thread overview: 107+ 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
[not found] ` <4A27BBCA.5020606-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-04 21:32 ` Mike Waychison
2009-06-05 3:03 ` Bharata B Rao
2009-06-05 3:07 ` Balbir Singh
2009-06-04 21:32 ` Mike Waychison
2009-06-05 3:03 ` Bharata B Rao
[not found] ` <20090605030309.GA3872-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-05 3:33 ` Avi Kivity
2009-06-05 3:33 ` Avi Kivity
[not found] ` <4A28921C.6010802-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 4:37 ` Balbir Singh
2009-06-05 4:37 ` Balbir Singh
[not found] ` <661de9470906042137u603e2997n80c270bf7f6191ad-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-05 4:44 ` Avi Kivity
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
[not found] ` <4A28A882.8070503-ZIRUuHA3oDzQT0dZR+AlfA@public.gmane.org>
2009-06-05 5:13 ` Balbir Singh
2009-06-05 5:10 ` Balbir Singh
[not found] ` <20090605051050.GB11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 5:21 ` Avi Kivity
2009-06-05 5:21 ` Avi Kivity
[not found] ` <4A28AB67.7040800-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 5:27 ` Balbir Singh
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 9:39 ` Balbir Singh
[not found] ` <20090605093947.GJ11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 13:14 ` Avi Kivity
2009-06-05 13:14 ` Avi Kivity
[not found] ` <4A291A2F.3090201-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 13:42 ` Balbir Singh
2009-06-05 13:42 ` Balbir Singh
2009-06-07 6:09 ` Avi Kivity
[not found] ` <661de9470906050642s7774d601l53e366c77ffa7475-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-07 6:09 ` Avi Kivity
2009-06-05 14:54 ` Chris Friesen
2009-06-05 14:54 ` Chris Friesen
2009-06-07 6:10 ` Avi Kivity
[not found] ` <4A293196.2060006-ZIRUuHA3oDzQT0dZR+AlfA@public.gmane.org>
2009-06-07 6:10 ` Avi Kivity
[not found] ` <4A28B4CE.4010004-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 8:16 ` Bharata B Rao
2009-06-05 8:16 ` Bharata B Rao
2009-06-07 6:04 ` Avi Kivity
[not found] ` <4A2B5881.9060204-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-07 16:14 ` Bharata B Rao
2009-06-07 16:14 ` Bharata B Rao
[not found] ` <20090605081651.GD3872-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-07 6:04 ` Avi Kivity
2009-06-05 9:39 ` Balbir Singh
2009-06-05 9:24 ` Balbir Singh
[not found] ` <20090605053159.GB3872-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-05 6:01 ` Avi Kivity
2009-06-05 9:24 ` Balbir Singh
[not found] ` <20090605052755.GE11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 5:31 ` Bharata B Rao
2009-06-05 6:03 ` Avi Kivity
2009-06-05 6:03 ` Avi Kivity
2009-06-05 6:32 ` Bharata B Rao
2009-06-05 12:57 ` Avi Kivity
[not found] ` <20090605063243.GC3872-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-05 12:57 ` Avi Kivity
[not found] ` <4A28B539.3050001-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 6:32 ` Bharata B Rao
[not found] ` <20090605044946.GA11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 5:09 ` Chris Friesen
2009-06-05 5:10 ` Balbir Singh
2009-06-05 5:16 ` Avi Kivity
2009-06-05 5:16 ` Avi Kivity
2009-06-05 5:20 ` Balbir Singh
[not found] ` <4A28AA25.4050206-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 5:20 ` Balbir Singh
[not found] ` <4A28A2AB.3060108-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 4:49 ` Balbir Singh
2009-06-05 3:07 ` Balbir Singh
[not found] ` <20090604053649.GA3701-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-04 12:19 ` Avi Kivity
2009-06-05 8:53 ` Paul Menage
2009-06-05 8:53 ` Paul Menage
2009-06-05 9:27 ` Bharata B Rao
2009-06-05 9:32 ` Paul Menage
[not found] ` <6599ad830906050232n11aa30d8xfcda0a279a482f32-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-05 9:48 ` Dhaval Giani
2009-06-05 9:48 ` Dhaval Giani
[not found] ` <20090605094811.GD4601-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2009-06-05 9:51 ` Paul Menage
2009-06-05 9:51 ` Paul Menage
[not found] ` <6599ad830906050251h18f4e037h182f61aa80a5b046-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-05 9:59 ` Dhaval Giani
2009-06-05 9:59 ` Dhaval Giani
[not found] ` <20090605095931.GE4601-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2009-06-05 10:03 ` Paul Menage
2009-06-05 10:03 ` Paul Menage
2009-06-08 8:50 ` Pavel Emelyanov
[not found] ` <6599ad830906050303r404c325anc60ded4f45a50b95-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-08 8:50 ` Pavel Emelyanov
[not found] ` <20090605092733.GA27486-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-05 9:32 ` Paul Menage
2009-06-05 9:36 ` Balbir Singh
[not found] ` <20090605093625.GI11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 9:48 ` Paul Menage
2009-06-05 9:48 ` Paul Menage
[not found] ` <6599ad830906050248m2c569e5bx44fb3bbddf46f8b1-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-05 9:55 ` Balbir Singh
2009-06-05 9:55 ` Balbir Singh
2009-06-05 9:57 ` Paul Menage
[not found] ` <20090605095527.GM11755-SINUvgVNF2CyUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2009-06-05 9:57 ` Paul Menage
2009-06-05 10:02 ` Paul Menage
2009-06-05 10:02 ` Paul Menage
2009-06-05 11:32 ` Srivatsa Vaddagiri
2009-06-05 12:18 ` Paul Menage
[not found] ` <6599ad830906050518t6cd7d477h36a187f2eaf55578-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-07 10:11 ` Srivatsa Vaddagiri
2009-06-07 10:11 ` Srivatsa Vaddagiri
2009-06-07 15:35 ` Balbir Singh
[not found] ` <661de9470906070835l383cd388h67e40a31be07aef6-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-08 4:37 ` Srivatsa Vaddagiri
2009-06-08 4:37 ` Srivatsa Vaddagiri
[not found] ` <20090607101120.GB16211-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-07 15:35 ` Balbir Singh
[not found] ` <20090605113217.GA20786-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2009-06-05 12:18 ` Paul Menage
2009-06-05 14:44 ` Chris Friesen
2009-06-05 14:44 ` Chris Friesen [this message]
[not found] ` <6599ad830906050153i1afd104fqe70f681317349142-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-05 9:27 ` Bharata B Rao
2009-06-05 9:36 ` Balbir Singh
2009-06-05 11:32 ` Srivatsa Vaddagiri
2009-06-05 13:02 ` Avi Kivity
2009-06-05 13:02 ` Avi Kivity
[not found] ` <4A291753.7090205-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2009-06-05 13:43 ` Dhaval Giani
2009-06-05 13:43 ` Dhaval Giani
[not found] ` <20090605134320.GA3994-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2009-06-05 14:45 ` Chris Friesen
2009-06-05 14:45 ` Chris Friesen
2009-06-05 9:02 ` Reinhard Tartler
-- strict thread matches above, loose matches on Subject: below --
2009-06-04 5:36 Bharata B Rao
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