From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 25 May 2007 10:14:11 -0700 From: Andrew Morton Subject: Re: [patch 0/6] Compound Page Enhancements Message-Id: <20070525101411.a95bd2ea.akpm@linux-foundation.org> In-Reply-To: References: <20070525051716.030494061@sgi.com> <20070524230032.554be39e.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, Mel Gorman , KAMEZAWA Hiroyuki , William Lee Irwin III List-ID: On Fri, 25 May 2007 07:03:22 -0700 (PDT) Christoph Lameter wrote: > On Thu, 24 May 2007, Andrew Morton wrote: > > > And looking back on it, I don't see the point in that PG_head_tail_mask > > hack either. We could have done > > > > static inline int page_tail(struct page *page) > > { > > return PageCompound(page) && (page->first_page != page); > > } > > But then PageHead(page) wont work anymore. pagehead->first_page is in use > for some other purpose. That's only because slub came along and screwed it all up. The compound page management used to be consistent, and simple. Specifically: that lockless_freelist afterthought rendered us unable to fix this mess. -- 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