From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) by mx1.pokylinux.org (Postfix) with ESMTP id 05F9C4C80050 for ; Mon, 6 Dec 2010 19:04:40 -0600 (CST) Received: from ALA-MAIL03.corp.ad.wrs.com (ala-mail03 [147.11.57.144]) by mail.windriver.com (8.14.3/8.14.3) with ESMTP id oB714eEp014403; Mon, 6 Dec 2010 17:04:40 -0800 (PST) Received: from ala-mail06.corp.ad.wrs.com ([147.11.57.147]) by ALA-MAIL03.corp.ad.wrs.com with Microsoft SMTPSVC(6.0.3790.1830); Mon, 6 Dec 2010 17:04:39 -0800 Received: from bruce-ashfields-macbook.local ([128.224.143.25]) by ala-mail06.corp.ad.wrs.com with Microsoft SMTPSVC(6.0.3790.1830); Mon, 6 Dec 2010 17:04:39 -0800 Message-ID: <4CFD8826.1080305@windriver.com> Date: Mon, 06 Dec 2010 20:04:38 -0500 From: Bruce Ashfield User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.13) Gecko/20101203 Thunderbird/3.1.7 MIME-Version: 1.0 To: Darren Hart References: <4CFD6C73.20006@linux.intel.com> <4CFD871A.10904@windriver.com> In-Reply-To: <4CFD871A.10904@windriver.com> X-OriginalArrivalTime: 07 Dec 2010 01:04:39.0764 (UTC) FILETIME=[B9660140:01CB95AA] Cc: poky@yoctoproject.org Subject: Re: PREEMPT_RT support X-BeenThere: poky@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Poky build system developer discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Dec 2010 01:04:41 -0000 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit On 10-12-06 8:00 PM, Bruce Ashfield wrote: > On 10-12-06 6:06 PM, Darren Hart wrote: >> I'm looking at how to best support PREEMPT_RT. We have a few things in >> the works which prevent the ideal scenario (which is just a new recipe >> using the preempt_rt branch in linux-yocto). >> >> 2.6.34 never had an -rt patch. The WR folks created one that builds and >> is undergoing review from tglx - but that doesn't appear to be near the >> top of his stack. 2.6.37 is still pending an -rt patch, also blocked on >> -tglx. > > We'll be doing one at WR eventually, so it will exist in > one form or another for version> 2.6.34. > >> >> I'm thinking of creating a meta-rt layer which would provide a latest >> -rt kernel and the rt-tests suite along with a non-graphical image >> definition that facilitates latency detection and rt performance >> measurement. poky-image-rt-test or something along those lines. >> >> Any objection to this approach? As we will eventually move these recipes >> into the core poky recipes, I'd suggest we put this in an >> "experimental/meta_rt" git repository. > > I'm worrying about this muddying the water with respect to the > -rt branches in the linux-yocto repositories. In particular if > we go *backward* from the 2.6.34 variant that we already have > (remember, that -rt kernel has been heavily abused for 9 > months now and is just as stable (probably more so for > non-x86) as anything else you'll find). > > Why can't we continue to consolidate these into fewer kernels > and recipes ? We can't share fixes and BSPs easily if everything > is kept separate. We can obviously pair the tests/utilities along > with the linux-yocto -rt branches, so I'd prefer that approach > and continue to work on improving the base that we already > have. I re-read this and my message really isn't clear. I like the approach. As we agreed before, that we need a separate recipe that highlights the -rt and builds from a known base. The tests and surrounding infrastructure are great, and we can have multiple sources for -rt goodness. I'm just suggesting that we use the 2.6.34 variant at least on a level playing field with the 2.6.33-rt, since our 2.6.34 can support all the official BSPs and features that have merged into the 0.9 kernel. Cheers, Bruce > > Cheers, > > Bruce > >> >> Thoughts? >> > > _______________________________________________ > poky mailing list > poky@yoctoproject.org > https://lists.yoctoproject.org/listinfo/poky