Re: [tip:irq/irqdomain] irqdomain: Introduce helper function irq_domain_add_hierarchy()

Jiang Liu
2014-11-29T15:21:17Z

On 2014/11/29 22:56, Borislav Petkov wrote:
> On Sat, Nov 29, 2014 at 10:29:33PM +0800, Jiang Liu wrote:
>> Thanks for reporting and fixing this. How about using GFP_ATOMIC
>> here?
>
> Well, I don't see the need to use GFP_ATOMIC if we absolutely don't have
> to. And in this case lockdep is, AFAICT, correct in saying that we still
> can do allocations with interrupts disabled, only not go down into fs
> and do all kinds of lock grabbing operations like page reclaim, writeout
> or whatever it is being done nowadays there.
>
> Yeah, this is also some old "no-no" in my memory which says that we
> should almost never use GFP_ATOMIC if it can be helped.
Thanks for the info about GFP_ATOMIC, originally I have an impression
that we should use GFP_ATOMIC when interrupt is disabled:(

>
> OTOH, I wonder if this code would rather need to hand down explicit gfp
> flags in case it should be able to do GFP_ATOMIC operations at some
> point...
>
> Thanks.
>