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

From: Alistair Popple
Date: Mon Jan 30 2023 - 06:16:50 EST



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?

> Jason