From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <41C8B678.40007@yahoo.com.au> Date: Wed, 22 Dec 2004 10:49:12 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [RFC][PATCH 0/10] alternate 4-level page tables patches References: <20041221093628.GA6231@wotan.suse.de> <20041221201927.GD15643@wotan.suse.de> In-Reply-To: <20041221201927.GD15643@wotan.suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Linus Torvalds , Hugh Dickins , Linux Memory Management , Andrew Morton List-ID: Andi Kleen wrote: >>Think of it this way: for random architecture X, the four-level page table >>patches really should make _no_ difference until they are enabled. So you >>can do 90% of the work, and be pretty confident that things work. Most >>importantly, if things _don't_ work before the thing has been enabled, >>that's a big clue ;) > > > My approach was to just do the straight forward conversions. The only > risk (from experience) so far was that things not compile when I forgot > one replacement, but when they compile they tend to work. > That is more or less the same with the 'pud' patches - the hard part is in the infrastructure and generic code, architectures are generally pretty simple. > I must say I would still prefer if my patches were applied instead > > of going through all of this again in a slightly different form. > e.g. who is doing all this "PUD" stuff? Nick's patch so far was only > a prototype and probably needs quite a bit more work and then a new > -mm testing cycle. > To summarise my position, I would like 'pud' to go in, because once one of the implementations gets into 2.6, it is going to be a lot harder to justify changing. And I personally like pud better (not the name, but the place) so I would prefer that to get in. Again, that is nothing against your implementation or your personal taste. So all I can do is put up my suggestion, and leave it to someone else to decide. I'm not so established/experienced in this code to be making big choices. I understand you'd be frustrated if 4level wasn't in 2.6.11, but as I said, I don't think the choice of pud over pml4 would necessarily cause such a delay. As far as I understand, you don't have any problem with the 'pud' implementation in principle? Nick -- 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