Re: [PATCH 1/2] block: blk-tag: Replace GFP_ATOMIC with GFP_KERNEL in __blk_queue_init_tags

[Jia-Ju Bai]

On 2018/1/25 11:44, Jens Axboe wrote:
> On 1/24/18 8:38 PM, Jia-Ju Bai wrote:
> > After checking all possible call chains to kmalloc here,
> > my tool finds that kmalloc is never called in atomic context.
> > Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
> >
> > This is found by a static analysis tool named DCNS written by myself.
> These two look OK to me, mostly.

It sounds good :)

> One issue is that blk_queue_init_tags()
> can be used to resize tags, in which case it's called with the
> queue lock held. Nobody is using it like that anymore, though. So I'd
> prefer if you did a v2 of this patch, and include a correction to that
> comment.

I am not sure what you mean...

Do you mean that the code in blk_queue_init_tags:
    else if (q->queue_tags) {
        ...
    }
can be deleted?

Or just delete the comment before blk_queue_init_tags?
 * Queue lock must be held here if the function is called to resize an
 * existing map.
 **/

Or add the description "The case that queue lock held is never used" in 
my patches?


Thanks,
Jia-Ju Bai