Re: GFP_ATOMIC allocations...

[Patrick Mansfield <patmans@us.ibm.com>]

On Wed, Aug 28, 2002 at 08:25:34PM -0400, Doug Ledford wrote:
> I'm looking through some of the new code that has been put in the kernel 
> scsi subsystem lately and I'm seeing a few of the same mistakes that the 
> old code made.  So, I'm pointing out one of them here.  There are lots of 
> places in the SCSI mid layer that are called outside of any spinlocks and 
> not from interrupt context where there is absolutely no need to use 
> GFP_ATOMIC allocations for memory.  In general, if you don't need to use 
> GFP_ATOMIC, then don't use it.  You're more likely to fail the allocation 
> and therefore fail the operation.  So, if you are working on a section of 
> code, please think about this when doing allocations and do whatever is 
> right for the code snippet you are currently hacking.  Fixing places in 
> the existing code that use GFP_ATOMIC needlessly is a plus ;-)

So, you think all (or most) of the GFP_ATOMIC's in scsi_scan.c should
be GFP_KERNEL? All the kmalloc calls should be at boot time, or via
insmod.

I was wondering about them, but left them to match the previous
scsi_scan.c code.

Do GFP_KERNEL alloc failures during boot time just return NULL?
(Given that there is really no memory left.) I'd hope so, but was
never sure.

I suppose I could change them and boot with mem=something-low and
see what happens.

-- Patrick