From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by nproxy.gmail.com with SMTP id l23so218022nfc for ; Thu, 08 Dec 2005 11:20:33 -0800 (PST) Message-ID: <84144f020512081120u428ebd6eud0566a7d57a7726a@mail.gmail.com> Date: Thu, 8 Dec 2005 21:20:33 +0200 From: Pekka Enberg Subject: Re: allowed pages in the block later, was Re: [Ext2-devel] [PATCH] ext3: avoid sending down non-refcounted pages In-Reply-To: <439879ED.5050706@cs.wisc.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Content-Disposition: inline References: <20051208180900T.fujita.tomonori@lab.ntt.co.jp> <20051208101833.GM14509@schatzie.adilger.int> <20051208134239.GA13376@infradead.org> <439878E4.6060505@cs.wisc.edu> <439879ED.5050706@cs.wisc.edu> Sender: owner-linux-mm@kvack.org Return-Path: To: Mike Christie Cc: open-iscsi@googlegroups.com, Christoph Hellwig , FUJITA Tomonori , linux-fsdevel@vger.kernel.org, ext2-devel@lists.sourceforge.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Hi, On 12/8/05, Mike Christie wrote: > Or there is not a way to do kmalloc(GFP_BLK) that gives us the right > type of memory is there? The slab allocator uses page->lru for special purposes. See page_{set|get}_{cache|slab} in mm/slab.c. They are used by kfree(), ksize() and slab debugging code to lookup the cache and slab an void pointer belongs to. But, if you just need put_page and get_page, couldn't you do something like the following? Pekka Index: 2.6/mm/swap.c =================================================================== --- 2.6.orig/mm/swap.c +++ 2.6/mm/swap.c @@ -36,6 +36,9 @@ int page_cluster; void put_page(struct page *page) { + if (unlikely(PageSlab(page))) + return; + if (unlikely(PageCompound(page))) { page = (struct page *)page_private(page); if (put_page_testzero(page)) { Index: 2.6/include/linux/mm.h =================================================================== --- 2.6.orig/include/linux/mm.h +++ 2.6/include/linux/mm.h @@ -322,6 +322,9 @@ static inline int page_count(struct page static inline void get_page(struct page *page) { + if (unlikely(PageSlab(page))) + return; + if (unlikely(PageCompound(page))) page = (struct page *)page_private(page); atomic_inc(&page->_count); -- 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