From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m3UKpp7o007467 for ; Wed, 30 Apr 2008 16:51:51 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m3UKpprT220412 for ; Wed, 30 Apr 2008 16:51:51 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m3UKpoQd014039 for ; Wed, 30 Apr 2008 16:51:51 -0400 Date: Wed, 30 Apr 2008 13:51:49 -0700 From: Nishanth Aravamudan Subject: Re: [patch 17/18] x86: add hugepagesz option on 64-bit Message-ID: <20080430205149.GE6903@us.ibm.com> References: <20080423015302.745723000@nick.local0.net> <20080423015431.462123000@nick.local0.net> <20080430193416.GE8597@us.ibm.com> <20080430195237.GE20451@one.firstfloor.org> <20080430200249.GA6903@us.ibm.com> <20080430201932.GH20451@one.firstfloor.org> <20080430202303.GB6903@us.ibm.com> <20080430204509.GJ20451@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080430204509.GJ20451@one.firstfloor.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: npiggin@suse.de, akpm@linux-foundation.org, linux-mm@kvack.org, kniht@linux.vnet.ibm.com, abh@cray.com, wli@holomorphy.com List-ID: On 30.04.2008 [22:45:09 +0200], Andi Kleen wrote: > > If so, I'll hold off > > on any further review. > > That's not what I asked for. Some of your comments were very useful > by pointing to real bugs and other problems, just some others were > not. Please continue reviewing, just make sure that all the comments > are focused on improving that particular code in the concrete current > application. I will focus on this, thanks for the feedback. Per my just-sent mail, I'm not sure what the "concrete application" is for 1G pages -- either a custom application or using libhugetlbfs with 1G pages. And the latter is where most of my comments are coming from. When I've been making nit-picky comments, I've tried to prefix them with "Nit". Those have mostly been cosmetic or style-issues that simply show up obviously in the diffs. > For example the bulk of the changes needed for PPC I expect will just > be an additional add on patchkit. I agree. But it might be nice to minimize the churn and be aware of any gotchas ahead of time. Hence why I asked yourself and Nick as the original authors about the separation between arch-independent and arch-dependent code. x86_64 seems to be relatively easy in this regard, while power requires more state per-hugepagesize. > > > The hugetlbfs code actually doesn't claim that. > > > > The hugetlb.c code is architecture independent and roughly generic (it > > doesn't know a whole lot about the underlying architecture itself). > > hstates are defined and used in this independent code -- hence my > > perspective that we want to make sure it is flexible enough to handle > > other architectures than x86_64, or at least easily extensible to them. > > It is extensible to them, but with some further changes (that is what > the patchkit claimed) > > For power I think it would be best if you just started on the > incremental patches needed (in fact there were already such an addon, > perhaps that can be just improved) Agreed, I'm starting to look at that with Jon. > > Well, Nick was talking about adding the powerpc bits to his stack > > when he submited for -mm, so these discussions should be happening > > now, AFAICT. > > The whole thing is work in progress and will undoubtedly change more > before it is really used. Nothing is put in stone yet. Thanks, Nish -- 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