From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161044AbWASRi0 (ORCPT ); Thu, 19 Jan 2006 12:38:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161043AbWASRi0 (ORCPT ); Thu, 19 Jan 2006 12:38:26 -0500 Received: from ns.suse.de ([195.135.220.2]:37031 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1161044AbWASRiZ (ORCPT ); Thu, 19 Jan 2006 12:38:25 -0500 Date: Thu, 19 Jan 2006 18:38:15 +0100 From: Nick Piggin To: Linus Torvalds Cc: Nick Piggin , Linux Memory Management , Linux Kernel Mailing List , Hugh Dickins , Andrew Morton , Andrea Arcangeli , David Miller Subject: Re: [patch 0/4] mm: de-skew page refcount Message-ID: <20060119173815.GA6564@wotan.suse.de> References: <20060118024106.10241.69438.sendpatchset@linux.site> <20060118170558.GE28418@wotan.suse.de> <20060119140039.GA958@wotan.suse.de> <20060119170656.GA9904@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 19, 2006 at 09:27:14AM -0800, Linus Torvalds wrote: > > > On Thu, 19 Jan 2006, Nick Piggin wrote: > > > > Hmm... this is what the de-skew patch _did_ (although it was wrapped > > in a function called get_page_unless_zero), in fact the main aim was > > to prevent this twiddling and the de-skewing was just a nice side effect > > (I guess the patch title is misleading). > > > > So I'm confused... > > The thing I minded was the _other_ changes, namely the de-skewing itself. > It seemed totally unnecessary to what you claimed was the point of the > patch. > > So I objected to the patch on the grounds that it did what you claimed > badly. All the _optimization_ was totally independent of that de-skewing, > and the de-skewing was a potential un-optimization. > No longer confused... > But if you do the optimizations as one independent set of patches, and > _then_ do the counter thing as a "simplify logic" patch, I don't see that > as a problem. > > Side note: I may be crazy, but for me when merging, one of the biggest > things is "does this pass my 'makes sense' detector". I look less at the > end result, than I actually look at the _change_. See? > > That's why two separate patches that do the same thing as one combined > patch may make sense, even if the _combined_ one does not (it could go the > other way too, obviously). > I agree, and the patches really are cleaner this way too, so again, thanks for the input on them. I'll resend soonish (with a trimmed cc list). Nick