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

[Jason Gunthorpe]

On Mon, Jan 30, 2023 at 10:12:43PM +1100, Alistair Popple wrote:
> 
> Jason Gunthorpe <jgg@xxxxxxxxxx> writes:
> 
> > On Tue, Jan 24, 2023 at 04:42:38PM +1100, Alistair Popple wrote:
> >> Convert io_uring to use vm_account instead of directly charging pages
> >> against the user/mm. Rather than charge pages to both user->locked_vm
> >> and mm->pinned_vm this will only charge pages to user->locked_vm.
> >
> > I think this is a mistake in the first patch, the pinned_vm should
> > still increment (but not checked against the rlimit), though its main
> > purpose in this mode is for debugging in proc.
> 
> Sorry, didn't quite follow - are you saying we should always increment
> mm->pinned_vm and only use VM_ACCOUNT_USER vs. TASK to select which one
> the rlimit is enforced against?

yes pinned_vm was created primarily a debugging counter in proc

Jason