From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f179.google.com (mail-pd0-f179.google.com [209.85.192.179]) by kanga.kvack.org (Postfix) with ESMTP id A8E4F6B0031 for ; Mon, 2 Jun 2014 12:48:05 -0400 (EDT) Received: by mail-pd0-f179.google.com with SMTP id fp1so3604913pdb.38 for ; Mon, 02 Jun 2014 09:48:05 -0700 (PDT) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTP id pr9si16417235pbc.175.2014.06.02.09.48.04 for ; Mon, 02 Jun 2014 09:48:04 -0700 (PDT) Message-ID: <538CAA13.2080708@intel.com> Date: Mon, 02 Jun 2014 09:45:07 -0700 From: Dave Hansen MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: 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 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org