On Wed, Jan 24, 2018 at 08:34:14PM -0700, Jens Axboe wrote:

On 1/24/18 7:46 PM, Jia-Ju Bai wrote:

quoted

The function ioc_create_icq here is not 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.

But it's running off the IO submission path, so by definition the GFP
mask cannot include anything that will do IO. GFP_KERNEL will make
it deadlock prone.

It could be GFP_NOIO, but that's also overlooking the fact that we can
have preemption disabled here.

We have REQ_NOWAIT request too, so GFP_NOIO isn't OK too.

-- 
Ming