From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx147.postini.com [74.125.245.147]) by kanga.kvack.org (Postfix) with SMTP id ECBF86B004D for ; Fri, 16 Nov 2012 13:04:09 -0500 (EST) Received: by mail-ee0-f41.google.com with SMTP id d41so2195434eek.14 for ; Fri, 16 Nov 2012 10:04:08 -0800 (PST) Date: Fri, 16 Nov 2012 19:04:04 +0100 From: Ingo Molnar Subject: Re: [PATCH 06/43] mm: numa: Make pte_numa() and pmd_numa() a generic implementation Message-ID: <20121116180404.GA4728@gmail.com> References: <1353064973-26082-1-git-send-email-mgorman@suse.de> <1353064973-26082-7-git-send-email-mgorman@suse.de> <50A648FF.2040707@redhat.com> <20121116144109.GA8218@suse.de> <20121116160852.GA4302@gmail.com> <20121116165606.GE8218@suse.de> <20121116171243.GA4697@gmail.com> <20121116174853.GF8218@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121116174853.GF8218@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Linus Torvalds , Rik van Riel , Peter Zijlstra , Andrea Arcangeli , Johannes Weiner , Hugh Dickins , Thomas Gleixner , Andrew Morton , Linux-MM , LKML * Mel Gorman wrote: > That said, your approach just ends up being heavier. [...] Well, it's more fundamental than just whether to inline or not (which I think should be a separate optimization and I won't object to two-instruction variants the slightest) - but you ended up open-coding change_protection() via: change_prot_numa_range() et al which is a far bigger problem... Do you have valid technical arguments in favor of that duplication? If you just embrace the PROT_NONE reuse approach of numa/core then 90% of the differences in your tree will disappear and you'll have a code base very close to where numa/core was 3 weeks ago already, modulo a handful of renames. It's not like PROT_NONE will go away anytime soon. PROT_NONE is available on every architecture, and we use the exact semantics of it in the scheduler, we just happen to drive it from a special worklet instead of a syscall, and happen to have a callback to the faults when they happen... Please stay open to that approach. Thanks, Ingo -- 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