On Fri, Nov 08, 2013 at 10:42:51AM -0500, Konrad Rzeszutek Wilk wrote: > On Fri, Nov 08, 2013 at 07:15:00AM -0800, Daniel Kiper wrote: > > On Fri, Nov 08, 2013 at 02:01:28PM +0000, Andrew Cooper wrote: > > > On 08/11/13 13:19, Jan Beulich wrote: > > > >>>> On 08.11.13 at 14:13, David Vrabel <david.vrabel at citrix.com> wrote: > > > >> Keir, > > > >> > > > >> Sorry, forgot to CC you on this series. > > > >> > > > >> Can we have your opinion on whether this kexec series can be merged? > > > >> And if not, what further work and/or testing is required? > > > > Just to clarify - unless I missed something, there was still no > > > > review of this from Daniel or someone else known to be > > > > familiar with the subject. If Keir gave his ack, formally this > > > > could go in, but I wouldn't feel too well with that (the more > > > > that apart from not having reviewed it, Daniel seems to also > > > > continue to have problems with it). > > > > > > > > Jan > > > > > > Can I have myself deemed to be familiar with the subject as far as this > > > is concerned? > > > > > > A noticeable quantity of my contributions to Xen have been in the kexec > > > / crash areas, and I am the author of the xen-crashdump-analyser. > > > > > > I do realise that I certainly not impartial as far as this series is > > > concerned, being a co-developer. > > > > > > Davids statement of "the current implementation is so broken[1] and > > > useless[2] that..." is completely accurate. It is frankly a miracle > > > that the current code ever worked at all (and from XenServers point of > > > view, failed far more often than it worked). > > > > > > > > > For reference, XenServer 6.2 shipped with approximately v7 of this > > > series, and an appropriate kexec-tools and xen-crashdump-analyser. > > > Since we put the code in, we have not had a single failure-to-kexec in > > > automated testing (both specific crash tests, and from unexpected host > > > crashes), whereas we were seeing reliable failures to crash on most of > > > our test infrastructure. > > > > > > In stark contrast to previous versions of XenServer, we have not had a > > > single customer reported host crash where the kexec path has failed. > > > There was one systematic failure where the HPSA driver was unhappy with > > > the state of the hardware, resulting in no root filesystem to write logs > > > to, and a repeated panic and Xen deadlock in the queued invalidation > > > codepath. > > > > Andrew, if it runs on all your hardware it does not mean that it runs > > everywhere. I have discovered the problem (I hope the last one) and it > > should be taken into consideration. Another question is what is the > > source of this problem. Maybe QEMU but it should be checked and not > > ignored. > > I think the question is that the feature freeze is the 18th - and whether > this single bug should halt the integration of this whole patchset. > > Or that it is OK to put in the patchset in and deal with the bugs > and not stall this initial patchset. I have never stated that I would like to block this patch series indefinitely due to this one bug (I am still not sure that this is a bug; Currently, I feel that I am only one person who tries to verify that). We have more then one week and I think that we are able to discover what is going on. If not I think that we can workout reasonable solution for this issue (as we did in other cases). Last but not least, I would like to underline that I wish that this patch series were included in Xen 4.4 too. However, it must be done in sensible way. Daniel
