From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Hongyang Subject: Re: [PATCH v2 COLOPre 11/13] tools/libxl: rename remus device to checkpoint device Date: Thu, 25 Jun 2015 13:00:14 +0800 Message-ID: <558B8ADE.3030606@cn.fujitsu.com> References: <1433734997-26570-1-git-send-email-yanghy@cn.fujitsu.com> <1433734997-26570-12-git-send-email-yanghy@cn.fujitsu.com> <20150612133046.GQ14606@zion.uk.xensource.com> <20150612133534.GR14606@zion.uk.xensource.com> <21882.62317.609108.131152@mariner.uk.xensource.com> <557E2E52.3070405@cn.fujitsu.com> <20150615162459.GI10177@zion.uk.xensource.com> <1434452000.13744.100.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1434452000.13744.100.camel@citrix.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 , Wei Liu Cc: eddie.dong@intel.com, wency@cn.fujitsu.com, andrew.cooper3@citrix.com, yunhong.jiang@intel.com, Ian Jackson , xen-devel@lists.xen.org, guijianfeng@cn.fujitsu.com, rshriram@cs.ubc.ca List-Id: xen-devel@lists.xenproject.org On 06/16/2015 06:53 PM, Ian Campbell wrote: > On Mon, 2015-06-15 at 17:24 +0100, Wei Liu wrote: >> On Mon, Jun 15, 2015 at 09:45:54AM +0800, Yang Hongyang wrote: >>> >>> >>> On 06/12/2015 10:57 PM, Ian Jackson wrote: >>>> Wei Liu writes ("Re: [Xen-devel] [PATCH v2 COLOPre 11/13] tools/libxl: rename remus device to checkpoint device"): >>>>> On Fri, Jun 12, 2015 at 02:30:46PM +0100, Wei Liu wrote: >>>>>> On Mon, Jun 08, 2015 at 11:43:15AM +0800, Yang Hongyang wrote: >>>>>>> - (-18, "REMUS_DEVOPS_DOES_NOT_MATCH"), >>>>>>> - (-19, "REMUS_DEVICE_NOT_SUPPORTED"), >>>>>>> + (-18, "CHECKPOINT_DEVOPS_DOES_NOT_MATCH"), >>>>>>> + (-19, "CHECKPOINT_DEVICE_NOT_SUPPORTED"), >>>>>> >>>>>> You should add two new error numbers. >>>>>> >>>>> >>>>> And in that case you might also need to go through all places to make >>>>> sure the correct error numbers are return. I.e. old remus code path >>>>> still returns REMUS error code and new CHECKPOINT code path returns new >>>>> error code. >>>>> >>>>> I merely speak from API backward compatibility point of view. If you >>>>> think what I suggest doesn't make sense, please let me know. >>>> >>>> To me this line of reasons prompts me to ask: what would be wrong with >>>> leaving the word REMUS in the error names, and simply updating the >>>> descriptions ? >>>> >>>> After all AFIACT the circumstances are very similar. I don't think it >>>> makes sense to require libxl to do something like >>>> rc = were_we_doing_colo_not_remus ? CHECKPOINT_BLAH : REMUS_BLAH; >>>> >>>> Please to contradict me if I have misunderstood... >>> >>> COLO and REMUS both are checkpoint device. We use checkpoint device layer >>> as a more abstract layer for both COLO and REMUS, come to the error code, >>> these can be used by both COLO and REMUS. So we don't distinguish if we >>> are doing COLO or REMUS, uses are aware of what they're executing(colo >>> or remus). >>> >> >> Right. So continue using REMUS_ error code is fine. > > Seems like it would also be OK to switch the name and then in libxl,h > > #ifdef LIB_API_VERSION < 0xWHENEVER > #define REMUS_BLAH CHECKPOINT_BLAH > #define ... > #endif > > _If_ we think the new names make more sense going fwd... Well, I think the new names are better, I also think it is safe to just rename them, I don't find any other users using these error codes except Remus/COLO, it is only used by Remus/COLO internally. > > > . > -- Thanks, Yang.