From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f47.google.com (mail-pa0-f47.google.com [209.85.220.47]) by kanga.kvack.org (Postfix) with ESMTP id E22136B0031 for ; Mon, 2 Jun 2014 14:19:36 -0400 (EDT) Received: by mail-pa0-f47.google.com with SMTP id ld10so4469660pab.34 for ; Mon, 02 Jun 2014 11:19:36 -0700 (PDT) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id gq8si16776022pbc.50.2014.06.02.11.19.35 for ; Mon, 02 Jun 2014 11:19:35 -0700 (PDT) Message-ID: <538CC026.4030008@intel.com> Date: Mon, 02 Jun 2014 11:19:18 -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> <538CAA13.2080708@intel.com> <538cb12a.8518c20a.1a51.ffff9761SMTPIN_ADDED_BROKEN@mx.google.com> In-Reply-To: <538cb12a.8518c20a.1a51.ffff9761SMTPIN_ADDED_BROKEN@mx.google.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: Andrew Morton , Konstantin Khlebnikov , Wu Fengguang , Arnaldo Carvalho de Melo , Borislav Petkov , "Kirill A. Shutemov" , Johannes Weiner , Rusty Russell , David Miller , Andres Freund , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 06/02/2014 10:14 AM, Naoya Horiguchi wrote: > Yes, that's necessary to consider (but I haven't done, sorry), > so I'm thinking of moving this definition to the new file > include/uapi/linux/pagecache.h and let it be imported from the > userspace programs. Is it fine? Yep, although I'd probably also explicitly separate the definitions of the user-exposed ones from the kernel-internal ones. We want to make this hard to screw up. I can see why we might want to expose dirty and writeback out to userspace, especially since we already expose the aggregate, system-wide view in /proc/meminfo. But, what about PAGECACHE_TAG_TOWRITE? I really can't think of a good reason why userspace would ever care about it or consider it different from PAGECACHE_TAG_DIRTY. -- 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