iSCSI initiator driver beta version, testers wanted
Scott Long
scottl at samsco.org
Sat Mar 19 07:10:32 PST 2005
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
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