Re: [PATCH 09/19] io_uring: convert to use vm_account

[Jason Gunthorpe]

On Tue, Feb 07, 2023 at 07:28:56AM -0700, Jens Axboe wrote:

> Outside of that, we're now doubling the amount of memory associated with
> tracking this. That isn't necessarily a showstopper, but it is not
> ideal. I didn't take a look at the other conversions (again, because
> they were not sent to me), but seems like the task_struct and flags
> could just be passed in as they may very well be known to many/most
> callers?

For places doing the mm accounting type it cannot use the task struct
as the underlying mm can be replaced and keep the task, IIRC.

We just had a bug in VFIO related to this..

If we could go back from the mm to the task (even a from a destroyed
mm though) that might work to reduce storage?

Jason