Subject: Re: [PATCH 09/14] resource limits: track highwater mark of locked memory

From: Oleg Nesterov <[email-masked]>
Date: Fri, 15 Jul 2016 17:14:08 +0200

On 07/15, Topi Miettinen wrote:
>
> Track maximum size of locked memory, to be able to configure
> RLIMIT_MEMLOCK resource limits. The information is available
> with taskstats and cgroupstats netlink socket.

So I personally still dislike the very idea of this series... but I won't
argue if you convince maintainers.

> @@ -2020,6 +2020,10 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
>  		return -ENOMEM;
>  
>  	update_resource_highwatermark(RLIMIT_STACK, actual_size);
> +	if (vma->vm_flags & VM_LOCKED)
> +		update_resource_highwatermark(RLIMIT_MEMLOCK,
> +					      (mm->locked_vm + grow) <<
> +					      PAGE_SHIFT);

Btw this is not right. The same for the previous patch which tracks
RLIMIT_STACK. The "current" task can debugger/etc.

Yes, yes, this just reminds that the whole rlimit logic in this path
is broken but still...

Oleg.