Messages in this thread |  | | From | Reto Baettig <> | Subject | Re: io_request_lock question (2.2) | Date | Fri, 8 Dec 2000 16:10:38 -0800 (PST) |
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> > > > On Fri, 8 Dec 2000, Alan Cox wrote: > > > > Yes, and I believe that this is what's broken about the SCSI midlayer. The the > > > io_request_lock cannot be completely released in a SCSI HBA because the flags > > > > You can drop it with spin_unlock_irq and that is fine. I do that with no > > problems in the I2O scsi driver for example > > I am (like, I think I *finally* got locking sorta right in my QLogic driver), > but doesn't this still leave ints blocked for this CPU at least? > > -matt > > >
I am actually concerned about the following case:
The add_request ON CPU_1 function calls spin_lock_irqsave(&io_request_lock,flags);
Our I/O Function unlocks the spinlock and goes to sleep.
Finally, the add_request function, NOW ON CPU_2 calls spin_unlock_irqrestore(&io_request_lock,flags); and restores the flags of CPU_1 on CPU_2.
What am I missing? Are the flags which we restore valid for all the CPU's the same?
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