Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753535Ab3EOXFf (ORCPT ); Wed, 15 May 2013 19:05:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34502 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221Ab3EOXFe (ORCPT ); Wed, 15 May 2013 19:05:34 -0400 Date: Wed, 15 May 2013 16:05:32 -0700 From: Andrew Morton To: Oskar Andero Cc: , , Hugh Dickins , Greg Kroah-Hartman , Radovan Lekanovic , David Rientjes Subject: Re: [RFC PATCH 0/2] return value from shrinkers Message-Id: <20130515160532.c965e92707c354100e25f79b@linux-foundation.org> In-Reply-To: <1368454595-5121-1-git-send-email-oskar.andero@sonymobile.com> References: <1368454595-5121-1-git-send-email-oskar.andero@sonymobile.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1467 Lines: 32 On Mon, 13 May 2013 16:16:33 +0200 Oskar Andero wrote: > In a previous discussion on lkml it was noted that the shrinkers use the > magic value "-1" to signal that something went wrong. > > This patch-set implements the suggestion of instead using errno.h values > to return something more meaningful. > > The first patch simply changes the check from -1 to any negative value and > updates the comment accordingly. > > The second patch updates the shrinkers to return an errno.h value instead > of -1. Since this one spans over many different areas I need input on what is > a meaningful return value. Right now I used -EBUSY on everything for consitency. > > What do you say? Is this a good idea or does it make no sense at all? I don't see much point in it, really. Returning an errno implies that the errno will eventually be returned to userspace. But that isn't the case, so such a change is somewhat misleading. If we want the capability to return more than a binary yes/no message to callers then yes, we could/should enumerate the shrinker return values. But as that is a different concept from errnos, it should be done with a different and shrinker-specific namespace. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/