Re: [RFC-PATCH 1/2] mm: Add __GFP_NO_LOCKS flag

[Peter Zijlstra]

On Sat, Aug 15, 2020 at 01:14:53AM +0200, Thomas Gleixner wrote:

> #1 trivial fix is to force switching to an high prio thread or a soft
>    interrupt which does the allocation

Yeah, push the alocation out to another context. I did consider it, but
why bother?

Also, raising a softirq can't be done from every context, that's a whole
new problem. You can do irq_work I suppose, but not all architectures
support the self-IPI yet.

All in all, it's just more complexity than the fairly trivial
__alloc_page_lockless().

Whichever way around, we can't rely on the allocation.