Re: [PATCH] mm: larger stack guard gap, between vmas
From: Linus Torvalds
Date: Mon Jul 03 2017 - 20:05:45 EST
On Mon, Jul 3, 2017 at 4:55 PM, Ben Hutchings <ben@xxxxxxxxxxxxxxx> wrote:
> Firstly, some Rust programs are crashing on ppc64el with 64 KiB pages.
> Apparently Rust maps its own guard page at the lower limit of the stack
> (determined using pthread_getattr_np() and pthread_attr_getstack()). I
> don't think this ever actually worked for the main thread stack, but it
> now also blocks expansion as the default stack size of 8 MiB is smaller
> than the stack gap of 16 MiB. Would it make sense to skip over
> PROT_NONE mappings when checking whether it's safe to expand?
Also, the whole notion that the gap should be relative to the page
size never made sense to me. So I think we could/should just make the
default gap size be one megabyte, not that "256 pages" abortion.
> Secondly, LibreOffice is crashing on i386 when running components
> implemented in Java. I don't have a diagnosis for this yet.
Ugh. Nobody seeing this inside SuSe/Red Hat? I don't think I've heard