[Scst-devel] [ofa-general] WinOF_2_0_5/SRP initiator: slow reads and eventually hangs

[Vladislav Bolkhovitin]

Chris Worley, on 09/06/2009 05:41 PM wrote:
> On Sun, Sep 6, 2009 at 3:36 PM, Chris Worley<worleys at gmail.com> wrote:
>> On Sun, Sep 6, 2009 at 3:17 PM, Bart Van Assche<bart.vanassche at gmail.com> wrote:
>>> On Fri, Sep 4, 2009 at 1:20 AM, Chris Worley <worleys at gmail.com> wrote:
>>>> On Thu, Sep 3, 2009 at 11:38 AM, Chris Worley<worleys at gmail.com> wrote:
>>>>> I've used a couple of initiators (different systems) w/ different
>>>>> OSes, w/ different IB cards (all QDR) and different IB stacks
>>>>> (built-in vs. OFED) and can repeat the problem in all but the
>>>>> RHEL5.2/OFED 1.4.1 target and initiator (but, if the initiator is
>>>>> WinOF and the target is RHEL5.2/OFED1.4.1, then the problem does
>>>>> repeat).
>>>> Here's a twist: I used the Ubuntu initiator w/ one of the RHEL
>>>> targets, and the RHEL initiator (same machine as was running WinOF
>>>> from the beginning of this thread) w/ one of the Ubuntu targets: in
>>>> both cases, the problem does not repeat.
>>>>
>>>> That makes it sound like OFED is the cure on either side of the
>>>> connection, but does not explain the issue w/ WinOF (which does fail
>>>> w/ either Ununtu or RHEL targets).
>>> These results are strange. Regarding the Linux-only tests, I was
>>> assuming failure of a single component (Ubuntu SRP initiator, OFED SRP
>>> initiator, Ubuntu IB driver, OFED IB driver or SRP target), but for
>>> each of these components there is at least one test that passes and at
>>> least one test that fails. So either my assumption is wrong or one of
>>> the above test results is not repeatable. Do you have the time to
>>> repeat the Linux-only tests ?
>> Last night I was rerunning the RHEL5.2 initiator w/ Ubuntu client, and
>> the problem repeated; now, I can't repeat the case where it didn't
>> fail.  Still, no errors, other than the eventual timeouts previously
>> shown; the target thinks all is fine, the initiator is stuck.
> 
> ... and I haven't had any success w/ Ubuntu target and initiator, 8.10 or 9.04.

1. Try with kernel parameter maxcpus=1. It will somehow relax possible 
races you have, although not completely.

2. Try with another hardware, including motherboard. You can have 
something like http://lkml.org/lkml/2007/7/31/558 (not exactly it, of 
course)

> Chris
>> Chris
>>> Bart.
>>>