From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 1233A6B0126 for ; Wed, 22 Jul 2009 17:35:26 -0400 (EDT) Date: Wed, 22 Jul 2009 14:55:12 -0700 (PDT) From: "Li, Ming Chun" Subject: Re: [patch 5/4] mm: document is_page_cache_freeable() In-Reply-To: Message-ID: References: <1248166594-8859-1-git-send-email-hannes@cmpxchg.org> <1248166594-8859-4-git-send-email-hannes@cmpxchg.org> <20090722175031.GA3484@cmpxchg.org> <20090722175417.GA7059@cmpxchg.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Johannes Weiner , Andrew Morton , KOSAKI Motohiro , linux-mm@kvack.org List-ID: On Wed, 22 Jul 2009, Christoph Lameter wrote: > > > static inline int is_page_cache_freeable(struct page *page) > > { > > + /* > > + * A freeable page cache page is referenced only by the caller > > + * that isolated the page, the page cache itself and > > The page cache "itself"? This is the radix tree reference right? > I think you are right. I had trouble understanding this function, So I looked into it and found out the call path: add_to_page_cache_locked -> page_cache_get -> atomic_inc(&page->_count) Please correct me if I am wrong. Vincent Li Biomedical Research Center University of British Columbia -- 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