From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 4 Apr 2007 14:32:03 +0100 (BST) From: Hugh Dickins Subject: Re: [rfc] no ZERO_PAGE? In-Reply-To: <20070404130559.GD19587@v2.random> Message-ID: References: <20070329075805.GA6852@wotan.suse.de> <20070330024048.GG19407@wotan.suse.de> <20070404033726.GE18507@wotan.suse.de> <20070404102407.GA529@wotan.suse.de> <20070404130559.GD19587@v2.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Nick Piggin , Andrew Morton , Linus Torvalds , Linux Memory Management List , tee@sgi.com, holt@sgi.com, Linux Kernel Mailing List List-ID: On Wed, 4 Apr 2007, Andrea Arcangeli wrote: > On Wed, Apr 04, 2007 at 01:45:06PM +0100, Hugh Dickins wrote: > > I'm confused. CONFIG_ZERO_PAGE off is where we'd like to end up: how > > would turning CONFIG_ZERO_PAGE on in -rc kernels help us to get there? > > He most certainly meant on by default. Okay, I thought it more diplomatic to label myself as the confused one ;) > > I think if we do this, we also need a zeropage counter in the vm stats > so that we'll get a measure of the waste and it'll be possible to > identify apps to optimize/fix. That's a little unfortunate, since we'd then have to lose the win from this change, that we issue a writable zeroed page (when VM_WRITE) in do_anonymous_page, even when it's a read fault, saving subsequent fault. Wouldn't we? Or am I confused ;? Hugh -- 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