Re: aic7xxx driver potentially sleeping with spin lock held in

[Andrew Morton]

Piet/Pete Delaney wrote:
> 
> I'm getting a scsi problem in the  aic7xxx driver sleeping while the preempt_count() != 0.
> Looks like we are holding a spinlock where the slab allocator could go to sleep.
> 
> ...
> #5  0xc029104d in aic7xxx_alloc_aic_dev (p=0xc3f7d56c, SDptr=0xc3ed3c00) at drivers/scsi/aic7xxx_old.c:6636

This does an GFP_KERNEL allocation

> #6  0xc029717d in aic7xxx_queue (cmd=0xc3efca00, fn=0xc0280f04 <scsi_done>) at drivers/scsi/aic7xxx_old.c:10341
> #7  0xc0280a26 in scsi_dispatch_cmd (SCpnt=0xc3efca00) at drivers/scsi/scsi.c:852                                <--- spin lock grabed at Line 851 just prior to call to queuecommand()

OK.

> #8  0xc0285ed2 in scsi_request_fn (q=0xc3ed3c28) at drivers/scsi/scsi_lib.c:1061
> #9  0xc0253715 in blk_insert_request (q=0xc3ed3c28, rq=0xc3efc88c, at_head=0, data=0xc3efc800) at drivers/block/ll_rw_blk.c:1456

And this took the queue lock.

It's aic7xxx_old.c.   Presumably it is headed for the scrap
heap.  The allocation is a once-off startup thing.  Probably
not worth worrying about.