Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755650AbaFBQsG (ORCPT ); Mon, 2 Jun 2014 12:48:06 -0400 Received: from mga09.intel.com ([134.134.136.24]:58888 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753551AbaFBQsE (ORCPT ); Mon, 2 Jun 2014 12:48:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.98,957,1392192000"; d="scan'208";a="550310497" Message-ID: <538CAA13.2080708@intel.com> Date: Mon, 02 Jun 2014 09:45:07 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Naoya Horiguchi CC: akpm@linux-foundation.org, koct9i@gmail.com, fengguang.wu@intel.com, acme@redhat.com, bp@alien8.de, kirill@shutemov.name, hannes@cmpxchg.org, rusty@rustcorp.com.au, davem@davemloft.net, andres@2ndquadrant.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/3] replace PAGECACHE_TAG_* definition with enumeration References: <20140521193336.5df90456.akpm@linux-foundation.org> <1401686699-9723-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1401686699-9723-2-git-send-email-n-horiguchi@ah.jp.nec.com> <538CA269.6010300@intel.com> <1401727052-f7v7kykv@n-horiguchi@ah.jp.nec.com> In-Reply-To: <1401727052-f7v7kykv@n-horiguchi@ah.jp.nec.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/02/2014 09:37 AM, Naoya Horiguchi wrote: > On Mon, Jun 02, 2014 at 09:12:25AM -0700, Dave Hansen wrote: >> > On 06/01/2014 10:24 PM, Naoya Horiguchi wrote: >>> > > -#define PAGECACHE_TAG_DIRTY 0 >>> > > -#define PAGECACHE_TAG_WRITEBACK 1 >>> > > -#define PAGECACHE_TAG_TOWRITE 2 >>> > > +enum { >>> > > + PAGECACHE_TAG_DIRTY, >>> > > + PAGECACHE_TAG_WRITEBACK, >>> > > + PAGECACHE_TAG_TOWRITE, >>> > > + __NR_PAGECACHE_TAGS, >>> > > +}; >> > >> > Doesn't this end up exposing kernel-internal values out to a userspace >> > interface? Wouldn't that lock these values in to the ABI? > Yes, that would. I hope these PAGECACHE_TAG_* stuff is very basic > things and will never change drastically in the future (only added), > so it's unlikely to bother people about ABI breakage things. OK, so if I'm writing a userspace program, which header do I include pull these values in to my program? -- 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/