From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: megasas stops I/O when running kernel as dom0 under xen4.1/4.2 Date: Tue, 30 Aug 2011 13:11:29 +0100 Message-ID: <4E5CD371.4030609@citrix.com> References: <4E4916A3.9070106@leuphana.de> <4E4E56EE.2070801@citrix.com> <4E4E705E.3040505@leuphana.de> <4E4E79E8.3020808@citrix.com> <4E4E913C.40809@leuphana.de> <4E4E9423.8010904@citrix.com> <4E4EA725.30405@leuphana.de> <4E521BD5.2040609@citrix.com> <4E54E93D.7060301@citrix.com> <4E552D62.2000002@citrix.com> <20110824170919.GA14696@dumpdata.com> <4E5532C3.8090601@citrix.com> <4E57E2EC.4090406@citrix.com> <4E57E6C1.5060405@citrix.com> <4E5CD13B.6020101@leuphana.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4E5CD13B.6020101@leuphana.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andreas Olsowski Cc: "xen-devel@lists.xensource.com" , Fraser , Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org On 30/08/11 13:02, Andreas Olsowski wrote: > --snip-- > > Apologies - previous patch fails to compile (i forgot to hg qrefresh > > before sending - it has been a very long day). Try this patch. > Testing right now, so far it seems to do fine, patching worked, so did > compilation. > > A scenario that previously stopped io does no longer stop it. > > Ill give it a couple of more tries and days, but it sure looks good. > > Any chance of introducing this patch into xen-4.1-testing and making > it a part of the upcoming xen-4.1.2? > > > with best regards, > > Andreas > That is up to Keir. My opinion is that this patch is more of a hack than a solution, especially as it does involve changing the API for interrupt ops, but that does not necessarily prevent it from being included. I will soon be working on some significant changes to the interrupt code (cleanup of structures, cleanup of logic - specifically the logic which is now false with per-cpu IDTs) with an intension to upstream them, but whether these patches are suitable to backport is an entirely different question. On a completely different note, we have got in contact with LSI who are altering their driver to consider MSI interrupts as well as MSI-X interrupts, which will be sensible to take, as MSI interrupts will give you an order of magnitude faster disk IO, irrespective of the line level bug in Xen. ~Andrew -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com