From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [PATCH v10 9/9] libxl: vnuma topology configuration parser and doc Date: Fri, 12 Sep 2014 10:31:00 +0100 Message-ID: <20140912093100.GD31343@zion.uk.xensource.com> References: <1409718258-3276-1-git-send-email-ufimtseva@gmail.com> <1409718258-3276-7-git-send-email-ufimtseva@gmail.com> <1410455600.4005.230.camel@Solace.lan> <1410512550.4005.243.camel@Solace.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1410512550.4005.243.camel@Solace.lan> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli Cc: Keir Fraser , Ian Campbell , Stefano Stabellini , George Dunlap , Matt Wilson , Ian Jackson , "xen-devel@lists.xen.org" , Jan Beulich , Wei Liu , Elena Ufimtseva List-Id: xen-devel@lists.xenproject.org On Fri, Sep 12, 2014 at 11:02:30AM +0200, Dario Faggioli wrote: > [Adding Wei] > > On gio, 2014-09-11 at 22:04 -0400, Elena Ufimtseva wrote: > > Hello Dario > > > Hi, > > > Thank you for such a thorough review. > > > Yeah, well, sorry it took a bit! :-/ > Sorry from me as well. I've been tracking this discussion for some time but never weighted in because I needed to get my other 8 patches ready for the freeze. No pressure. ;-) > > Majority of comments make sense to me. > > > Cool. :-D > > > Now I wanted to ask about the memory ranges :) > > I am not sure at this point I should have them parsed in config file > > (for the case where vNUMA node has multiple ranges) and as Ian has > > mentioned I will be moving > > these ranges away from libxl build info. > > I guess for now It will be better to leave these ranges out of scope > > of parsing code. > > What do you think? > > > If, as I'm quite sure, with 'memory ranges' you're now talking about the > possibility of specifying more memory region for each node, yes, given > that we're keeping that out of the libxl interface, I'd live them out of > xl too. > Agreed. We just need to make the syntax backward compatible. > If, with 'memory ranges', you mean the possibility of specifying > different memory size for each node, I think I'd keep this. > > In fact, bbout memory, I'm fine with how you right now deal with > vnuma_mem (which I suggested to rename to "vnuma_memory" or > "vnuma_maxmem"), i.e.: > I don't thin vnuma_maxmem reflects what this parameter means. The list controls distribution of memory not the maximum amount. The sum of this list should be equal to maxmem= in config file. > vnuma_memory = [1024, 1024, 2048, 2048] > > When, in future, we will introduce toolstack support for defining nodes > with multiple memory regions, we can extend this syntax quite easily, to > something like > > vnuma_memory = ["128,896", 256,256,512"] > > with the following meaning: we have two nodes; node 0 has two regions, > one 128MB big, the other 896MB big. Node 1 has 3 regions, the first twos > 256MB big, the third 512MB big. > > Just to give an example. > > If we want, that can be even more specific, i.e.: > > vnuma_memory = ["128@0xffffaaa,896@0xccccdddd", ...] > > meaning: node 0 has one region 128MB big, starting at address 0xffffaaa, > and another 896MB big, starting at address 0xccccdddd (ISTR we agreed on > something very similar to this for Arianna's iomem series). > I think this syntax is good. Wei. > This is just an example, of course, the point being that the current > interface is good for now, and can be easily extended, in a backward > compatible way. > > This is my take on this, hoping I understood your question. Ian's > opinion is probably the one you want, though. :-) > > Regards, > Dario > > -- > <> (Raistlin Majere) > ----------------------------------------------------------------- > Dario Faggioli, Ph.D, http://about.me/dario.faggioli > Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) >