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: Fri, 19 Aug 2011 15:57:44 +0100 Message-ID: <4E4E79E8.3020808@citrix.com> References: <4E43E04B.8010401@leuphana.de> <20110811225119.GA3557@dumpdata.com> <4E44EE51.70802@leuphana.de> <201108151149.44053.simon.rowe@eu.citrix.com> <4E4916A3.9070106@leuphana.de> <4E4E56EE.2070801@citrix.com> <4E4E705E.3040505@leuphana.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4E4E705E.3040505@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" List-Id: xen-devel@lists.xenproject.org On 19/08/11 15:17, Andreas Olsowski wrote: > Am 19.08.2011 14:28, schrieb Andrew Cooper: >> On 15/08/11 13:52, Andreas Olsowski wrote: >>> On 08/15/2011 12:49 PM, Simon Rowe wrote: >>>> I've found adding >>>> >>>> options megaraid_sas poll_mode_io=1 >>>> >>>> makes both of the systems we're seeing this on stable. >>> ive been told to try that one and it works for me too (been running >>> test >>> io for roughly 5 minutes now). >>> >>> driver version >>> megasas: 00.00.05.30 Tue. Jan. 4 17:00:00 PDT 2011 >> >> Hello - I am now debugging. >> >> It seems that the megaraid_sas driver will try and use either MSI-X or >> legacy PCI interrupts mode, but will never try to use MSI. The box we >> can reproduce the problem on has MSI support but not MSI-X support. >> >> As an experiment, I put a single call to pci_enable_msi() in the >> megasas_probe_one() function, immediately after pci_set_master(). I now >> cannot reproduce the problem. >> >> Do any of the boxes you have which reproduce the problem set up MSI-X >> interrupts for the megasas driver, or are they all using legacy PCI >> interrupts? >> >> (I am also emailing an LSI contact asking why they do not use MSI >> interrupts) >> >> ~Andrew >> > > No the affected systems DO NOT use MSI-X > > Below is output from 3 Servers, xenturio1 and tarballerina are > affected (same old raid controller) whereas netcatarina is not (newer > raid controller). > > May i add, the 1078 series raid controller isnt listed on the LSI > homepage, the 9260 is. > > The affected servers are Dell PE2950 and R710. > Unaffectes is are the R610s. > > Hope this helps, below is some output of the servers: > > > root@xenturio1:~# cat /proc/interrupts |grep mega > 16: 2545 0 0 0 0 > 0 0 0 xen-pirq-ioapic-level megasas > root@xenturio1:~# lspci |grep LSI > 01:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS > 1078 (rev 04) > > > root@tarballerina:~# cat /proc/interrupts |grep mega > 33: 47264 0 0 0 0 > 0 0 0 xen-pirq-ioapic-level megasas > root@tarballerina:~# lspci |grep LSI > 03:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS > 1078 (rev 04) > > > root@netcatarina:~# cat /proc/interrupts |grep mega > 2237: 88684 0 0 0 0 > 0 0 0 xen-pirq-msi-x megasas > root@netcatarina:~# lspci |grep LSI > 03:00.0 RAID bus controller: LSI Logic / Symbios Logic LSI MegaSAS > 9260 (rev 05) > This further confirms my findings. Do you mind intserting a call to pci_enable_msi() in the probe function and see if that sorts out your two problem cases? -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com