Re: [PATCH 1/4] mm: Trial do_wp_page() simplification

Jason Gunthorpe
2021-02-02T17:16:55Z

On Tue, Feb 02, 2021 at 12:05:36PM -0500, Peter Xu wrote:

> > Gal, you could also MADV_DONTFORK this range if you are explicitly
> > allocating them via special mmap.
>
> Yeah I wanted to mention this one too but I just forgot when reply: the issue
> thread previously pasted smells like some people would like to drop
> MADV_DONTFORK, but if it's able to still be applied I don't know why
> not..

I want to drop the MADV_DONTFORK for dynamic data memory allocated by
the application layers (eg with malloc) without knowledge of how they
will be used.

This case is a buffer internal to the communication system that we
know at allocation time how it will be used; so an explicit,
deliberate, MADV_DONTFORK is fine

Jason