From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [PATCH 1 of 3] Support of getting scheduler defaults Date: Tue, 22 May 2012 14:58:58 +0200 Message-ID: <4FBB8D92.8050800@ts.fujitsu.com> References: <56c50b3f6cc3eb1de8b8.1337678212@nehalem1> <1337689344.10118.92.camel@zakaz.uk.xensource.com> <4FBB86AE.7010908@ts.fujitsu.com> <1337689975.10118.102.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1337689975.10118.102.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 05/22/2012 02:32 PM, Ian Campbell wrote: > On Tue, 2012-05-22 at 13:29 +0100, Juergen Gross wrote: >> On 05/22/2012 02:22 PM, Ian Campbell wrote: >>> On Tue, 2012-05-22 at 10:16 +0100, Juergen Gross wrote: >>>> Support a new sysctl schedop sub-command to get the scheduling defaults of a >>>> specific scheduler. >>> Why is XEN_DOMCTL_SCHEDOP_getinfo not sufficient here? >>> >>> Isn't it actually more useful/meaningful to get the current actual >>> setting rather than a default? >> When setting the parameters from the config file we have no domain yet which >> we would have to specify for XEN_DOMCTL_SCHEDOP_getinfo. I didn't want to >> parse part of the config only after domain creation. > That seems like another problem with doing this up front instead of > doing read-modify-write when we come to set the values for the domain. Do you think it would be okay to parse the scheduler config data _after_ domain creation? If yes, the read-modify-write approach is simple and always correct. If no, you will have to initialize the parameters to something scheduler specific, and not domain specific. >> A default should be okay, as this is what we want to modify. :-) >> The scheduler should initialize a new domain with this default, of course. > So I can't use this interface to change the current one of the current > settings for running a domain, while leaving the others at their current > value? I don't understand this sentence :-) ... > Which interface can I use for that and why isn't it the same as this > one? ... making it hard to answer to this one. :-) Nevertheless trying: you can change the scheduling parameters of a running domain with xl sched-credit/sched-sedf/... Juergen -- Juergen Gross Principal Developer Operating Systems PDG ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967 Fujitsu Technology Solutions e-mail: juergen.gross@ts.fujitsu.com Domagkstr. 28 Internet: ts.fujitsu.com D-80807 Muenchen Company details: ts.fujitsu.com/imprint.html