Re: [RFC PATCH 11/37] x86/mm: attempt speculative mm faults first

[Peter Zijlstra]

On Tue, Apr 06, 2021 at 06:44:36PM -0700, Michel Lespinasse wrote:
> --- a/arch/x86/mm/fault.c
> +++ b/arch/x86/mm/fault.c
> @@ -1219,6 +1219,8 @@ void do_user_addr_fault(struct pt_regs *regs,
>  	struct mm_struct *mm;
>  	vm_fault_t fault;
>  	unsigned int flags = FAULT_FLAG_DEFAULT;
> +	struct vm_area_struct pvma;

That's 200 bytes on-stack... I suppose that's just about acceptible, but
perhaps we need a comment in struct vm_area_struct to make people aware
this things lives on-stack and size really is an issue now.