From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 29 Jun 2005 23:22:30 +0200 From: Pavel Machek Subject: Re: [patch 2] mm: speculative get_page Message-ID: <20050629212230.GB17462@atrey.karlin.mff.cuni.cz> References: <42BF9CD1.2030102@yahoo.com.au> <42BF9D67.10509@yahoo.com.au> <42BF9D86.90204@yahoo.com.au> <42C14662.40809@shadowen.org> <42C14D93.7090303@yahoo.com.au> <1119974566.14830.111.camel@localhost> <20050629163132.GB13336@elf.ucw.cz> <1120070616.12143.4.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1120070616.12143.4.camel@localhost> Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Nick Piggin , Andy Whitcroft , linux-kernel , Linux Memory Management List-ID: Hi! > > > > I think there are a a few ways that bits can be reclaimed if we > > > > start digging. swsusp uses 2 which seems excessive though may be > > > > fully justified. > > > > > > They (swsusp) actually don't need the bits at all until suspend-time, at > > > all. Somebody coded up a "dynamic page flags" patch that let them kill > > > the page->flags use, but it didn't really go anywhere. Might be nice if > > > someone dug it up. I probably have a copy somewhere. > > > > Unfortunately that patch was rather ugly :-(. > > Do you think the idea was ugly, or just the implementation? Is there > something that you'd rather see? Well, implementation was ugly and idea was unneccesary because we still had bits left. We could spare bits for swsusp by defining "PageReserved | PageLocked => PageNosave" etc.... simply by choosing some otherwise unused combinations. swsusp is not performance critical... Pavel -- Boycott Kodak -- for their patent abuse against Java. -- 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: aart@kvack.org