From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi-Vw/NltI1exuRpAAqCnN02g@public.gmane.org>
Subject: Re: [PATCH V3][for-next] mm: add a new vector based madvise syscall
Date: Tue, 8 Dec 2015 07:18:08 +0100
Message-ID: <20151208061807.GO15533@two.firstfloor.org>
References: <7c6ce0f1fe29fc22faf72134f4e2674da8d3d149.1449532062.git.shli@fb.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Content-Disposition: inline
In-Reply-To: <7c6ce0f1fe29fc22faf72134f4e2674da8d3d149.1449532062.git.shli-b10kYP2dOMg@public.gmane.org>
Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: Shaohua Li <shli-b10kYP2dOMg@public.gmane.org>
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Kernel-team-b10kYP2dOMg@public.gmane.org, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Rik van Riel <riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Mel Gorman <mgorman-l3A5Bk7waGM@public.gmane.org>, Hugh Dickins <hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Andrea Arcangeli <aarcange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Andi Kleen <andi-Vw/NltI1exuRpAAqCnN02g@public.gmane.org>, Minchan Kim <minchan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
List-Id: linux-api@vger.kernel.org

> +	if (behavior != MADV_DONTNEED && behavior != MADV_FREE)
> +		return -EINVAL;

This limitations is kind of lame and makes it a special purpose hack.

It will also cause backwards compatibility issues if it needs
to be extended later.

How hard would it be to support all of madvise vectored?

That would also give much cleaner documentation.

-Andi