From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: linux-3.4 broken on chardonnay and huxelrebe (Re: [linux-3.4 test] 61301: regressions - FAIL) Date: Tue, 15 Sep 2015 09:47:38 +0100 Message-ID: <1442306858.3549.325.camel@citrix.com> References: <1441791846.24450.237.camel@citrix.com> <1441877560.24450.365.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1441877560.24450.365.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: osstest service owner , xen-devel@lists.xensource.com Cc: Ian.Jackson@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On Thu, 2015-09-10 at 10:32 +0100, Ian Campbell wrote: > The Chardonnay case suggests that either something has been backported into > 3.4.x which has broken things (current real flights, which reliably fail, > are running on 3.4.108) or that it is simply unreliable (or both). I think > I need to repeat things a few times to confirm. It turns out it was unreliable and these results were misleading. I setup an adhoc job which simply installed Xen and rebooted 5 times and 3.4.x (for x in increments of 10) failed reliably. In fact the fix wasn't until v3.7 -rc1 and some adhoc runs have fingered 65fe1f0f66a5 "ahci: implement aggressive SATA device sleep support"[0]. I'm running a few more tests to confirm but this looks reasonably certain. That commit is a new feature, so it really shouldn't have the affect of fixing bugs! I suspect this is something like a dodgy BIOS enabling the h/w extension, which breaks until the kernel became aware of it and either disables or explicitly copes with it being there. Once the confirmation tests have run I will lock the machine and have a poke around and see what I can see. I could then take it to the Linux AHCI maintainer but I suspect that a backport is only a slim possibility, as is someone taking the time to determine which bit of this feature happened to fix these systems. IOW I'm thinking that we should apply a minimum kernel version to chardonnay as well as huxelrebe (once that feature exists). Ian. [0] git.kernel.org/torvalds/c/65fe1f0f66a57380229a4ced844188103135f37b