From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750764AbWCUVor (ORCPT ); Tue, 21 Mar 2006 16:44:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750845AbWCUVor (ORCPT ); Tue, 21 Mar 2006 16:44:47 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:41892 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S1750764AbWCUVoq (ORCPT ); Tue, 21 Mar 2006 16:44:46 -0500 Subject: Re: [PATCH][5/8] proc: export mlocked pages info through "/proc/meminfo: Wired" From: Dave Hansen To: Stone Wang Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: References: Content-Type: text/plain Date: Tue, 21 Mar 2006 13:43:12 -0800 Message-Id: <1142977393.10906.204.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2006-03-20 at 08:37 -0500, Stone Wang wrote: > --- linux-2.6.15.orig/include/linux/mm.h 2006-01-02 22:21:10.000000000 -0500 > +++ linux-2.6.15/include/linux/mm.h 2006-03-07 01:49:12.000000000 -0500 > @@ -218,6 +221,10 @@ > unsigned long flags; /* Atomic flags, some possibly > * updated asynchronously */ > atomic_t _count; /* Usage count, see below. */ > + unsigned short wired_count; /* Count of wirings of the page. > + * If not zero,the page would be SetPageWired, > + * and put on Wired list of the zone. > + */ > atomic_t _mapcount; /* Count of ptes mapped in mms, > * to show when page is mapped > * & limit reverse map searches. We're usually pretty picky about adding stuff to 'struct page'. It _just_ fits inside a cacheline on most 32-bit architectures. Can this wired_count not be derived at runtime? It seems like it would be possible to run through all VMAs mapping the page, and determining how many of them are VM_LOCKED. Would that be too slow? Also, does it matter how many times it is locked, or just that _somebody_ has it locked? -- Dave