Re: [PATCH, RFC] block: set noio context in submit_bio_noacct_nocheck

[Christoph Hellwig]

On Thu, Jan 25, 2024 at 09:13:37AM -0700, Jens Axboe wrote:
> > Nono, you don't understand.  The plan is to remove GFP_NOIO
> > entirely.  Allocations should be done with GFP_KERNEL while under a
> > memalloc_noio_save().
> 
> I do understand, but thanks for the vote of confidence. Place the
> save/restore higher up, most likely actual IO submission isn't going to
> be the only (or even major) allocation potentially needed for the IO.

NOIO is defined as allocations that will not recurse into the I/O stack.
So for anything block based, entering the block layer is literally
the defined boundary where it should be used below.  So no, wrapping
every submit_bio into a context annotation doesn't make much sense.