Re: iSCSI initiator driver beta version, testers wanted
From: Scott Long (scottl_at_samsco.org)
Date: 03/19/05
- Previous message: Scott Long: "Re: iSCSI initiator driver beta version, testers wanted"
- In reply to: Scott Long: "Re: iSCSI initiator driver beta version, testers wanted"
- Next in thread: Danny Braniss: "Re: iSCSI initiator driver beta version, testers wanted"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Date: Sat, 19 Mar 2005 08:56:30 -0700 To: Danny Braniss <danny@cs.huji.ac.il>
Scott Long wrote:
> Danny Braniss wrote:
>
>>> with tags enabled, iSCSI is much faster, but it also causes a
>>> deadlock :-(
>>> this is what i run:
>>> newfs -U /<iscsi device>
>>> cd /<iscsi device>
>>> restore rf /home/file.dump
>>>
>>> on the same motherboard, a dual Xeon, with smp disabled all is OK
>>> with smp enabled restore gets stuck usualy waiting on biord.
>>> the iscsi driver shows that all requests have been done, the sniffing
>>> shows the same(ie all request have been done).
>>>
>>> so this leads me to think that there is some race condition that i'm not
>>> aware of in a SMP system, where xpt_done(ccb) is called while
>>> another process is calling biowait.
>>>
>>> another lead is that after restore gets stuck, the system slowly gets
>>> 'stalled'.
>>>
>>> any insight is most welcome!, i'm also stuck.
>>
>>
>>
>> ahh, hate talking to myself :-)
>>
>> grabbing Giant before calling xpt_done solved it, so the problem is
>> most probably in the CAM ...
>>
>> danny
>>
>>
>>
>
> No, you need to grab Giant when calling xpt_done(). I even put an
> assertion into CAM to make sure of that. Are you running with WITNESS
> and/or INVARIANTS enabled? Those would have caught this problem.
>
> Scott
Oops, I forgot to mention that I recently addressed this in 6-CURRENT.
Now, much of the rest of cam API still requires Giant to be held, but
xpt_done() does not. This only applies to 6-CURRENT, and I doubt that
it will be backported to 5-STABLE.
Scott
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
- Previous message: Scott Long: "Re: iSCSI initiator driver beta version, testers wanted"
- In reply to: Scott Long: "Re: iSCSI initiator driver beta version, testers wanted"
- Next in thread: Danny Braniss: "Re: iSCSI initiator driver beta version, testers wanted"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Relevant Pages
|
|
