From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [patch 8/8] Pageflags: Eliminate PG_xxx aliases Date: Fri, 7 Mar 2008 15:16:11 +1100 References: <20080305223815.574326323@sgi.com> <200803071320.16967.nickpiggin@yahoo.com.au> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200803071516.12268.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andrew Morton , ak@suse.de, Mel Gorman , apw@shadowen.org, KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , linux-mm@kvack.org List-ID: On Friday 07 March 2008 14:53, Christoph Lameter wrote: > On Fri, 7 Mar 2008, Nick Piggin wrote: > > > It avoids us having to deal with aliases in the future. > > > > It doesn't. You still have to deal with them. > > Sortof. > > You do not have to deal with it on the level of the PG_xxx enum constant. But that's the easy part, and the part that I think is actually useful because you get to explicitly see the aliases. > Yes you will have to deal with the aliases at the level of the > functions. Which is the hard part. > > > PG_xx at this > > > point is not unique which can be confusing. See the PG_reclaim in > > > mm/page_alloc.c. It also means PG_readahead. If I look for > > > handling of PG_readahead then I wont find it. > > > > You can't just pretend not to deal with aliases at that point > > in mm/page_alloc.c just becuase you only have one name for the > > bit position. > > If you only have one name for the bit position the you can localize the > aliases and uses of that bit. This means you can go from a bit that you > see set while debugging to the PG_xxx flag and then look for uses. Which > will turn up aliases. I don't understand how this would be any different from the current code except with the curent code, you only have to look for aliases in one place (ie. the PG_ definitions). -- 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