From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH 2/2] expert_mode: Add a new configuration option for expert users. Date: Wed, 17 Jul 2013 12:13:31 +0100 Message-ID: <51E67C5B.8030006@eu.citrix.com> References: <1373652532-24166-1-git-send-email-konrad.wilk@oracle.com> <1373652532-24166-3-git-send-email-konrad.wilk@oracle.com> <1373965455.4663.10.camel@kazak.uk.xensource.com> <20966.30808.647898.994541@mariner.uk.xensource.com> <51E679F6.6040305@eu.citrix.com> <1374059533.8960.31.camel@kazak.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: <1374059533.8960.31.camel@kazak.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: Konrad Rzeszutek Wilk , xen-devel@lists.xensource.com, Ian Jackson List-Id: xen-devel@lists.xenproject.org On 17/07/13 12:12, Ian Campbell wrote: > On Wed, 2013-07-17 at 12:03 +0100, George Dunlap wrote: >> On 17/07/13 11:56, Ian Jackson wrote: >>> Ian Campbell writes ("Re: [Xen-devel] [PATCH 2/2] expert_mode: Add a new configuration option for expert users."): >>>> On Fri, 2013-07-12 at 14:08 -0400, Konrad Rzeszutek Wilk wrote: >>>>> This could also be called 'seatbelt' option. >>>>> >>>>> libxl has a variety of checks where it will fail out an operation >>>>> unless the user has provided an --force (or --ignore) parameter. >>>>> Currently one such check is for the 'vcpu-set' command which >>>>> will error out if the count of virtual cpus is greater than the >>>>> physical cpus. This parameter will ignore such checks and allow >>>>> the user to do the operations without the need for override flags. >>>> Does this overlap somewhat with various commands which individually >>>> take a -f(orce) option? >>> Clearly it should disable all of those -f's too. >>> >>>>> +=item B >>>>> + >>>>> +Do not act on host performed checks that might lead to performance >>>>> +degradations. Currently checks are made for following operations: >>>>> + - C - if the number of VCPUs set for a guest is higher than the >>>>> + physical count the operation will error out. >>> I don't think this is a very coherent specification. Surely it should >>> override "all -f options" or something similar. >> I think that makes sense for some but not all. For example, for "xl >> shutdown", -f means "send an ACPI event if no PV drivers are detected". >> I don't think we'd want to change that behavior with such a switch. >> (Arguably -f was the wrong option to use for that in the first place, >> but it's a bit late for that now.) > That's -F (for fallback not force), deliberately avoiding -f for the > reasons you might think. > > If "xl shutdown -f" were to do anything it would probably be to act as > "xl destroy" (nb I don't think we should actually do that...) Ah, right. That makes sense. -G