On Sun, Jul 28, 2019 at 03:29:38PM +0300, Konstantin Khlebnikov wrote:
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -847,8 +847,11 @@ static long __get_user_pages(struct task_struct *tsk,
> struct mm_struct *mm,
> ret = -ERESTARTSYS;
> goto out;
> }
> - cond_resched();
>
> + /* Reclaim memory over high limit before stocking too much */
> + mem_cgroup_handle_over_high(true);
I'd rather this remained part of the try_charge() call. The code
comment in try_charge says this:
* We can perform reclaim here if __GFP_RECLAIM but let's
* always punt for simplicity and so that GFP_KERNEL can
* consistently be used during reclaim.
The simplicity argument doesn't hold true anymore once we have to add
manual calls into allocation sites. We should instead fix try_charge()
to do synchronous reclaim for __GFP_RECLAIM and only punt to userspace
return when actually needed.
