Re: Fw: 2.6.6-rc3 ia64 smp_call_function() called with interrupts disabled

[Christoph Hellwig <hch@infradead.org>]

On Mon, May 03, 2004 at 09:35:13PM +0100, Matthew Wilcox wrote:
> That patch is crap -- it only frees the memory on the error path, not
> the normal exit.  Since I got confused by this function, it struck me
> as not unreasonable that somebody else might also get confused by it
> and split it into two parts.
> 
> I simplified some of the code.  The old code took the lock, scanned
> through looking for a free slot, dropped the lock, allocated an sdp,
> grabbed the lock and checked the slot was still free, branching back
> if it had raced.  This rewrite assumes that we will find a slot and
> allocates an sdp in advance.
> 
> Does anybody like this patch?  It survived booting on my test box which
> only has one scsi device.  More testing welcomed.

Better than what was there, but I still don't like it.  A global array
of devices is just utter crap.  Every entry point from scsi already has
struct scsi_device from which we can derive the sg-specific portion easily,
and for anything else (from a quick look that seems to be only procfs
stuff which should fade out anyway) a linear search on a linked list
is okay.

btw, why are we vmalloc()ing Sg_device?