From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4303EBC2.4030603@yahoo.com.au> Date: Thu, 18 Aug 2005 12:00:34 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: pagefault scalability patches References: <20050817151723.48c948c7.akpm@osdl.org> In-Reply-To: <20050817151723.48c948c7.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Linus Torvalds , Hugh Dickins , Christoph Lameter , Nick Piggin , linux-mm@kvack.org List-ID: Andrew Morton wrote: >These are getting in the way now, and I need to make a go/no-go decision. > >I have vague feelings of ickiness with the patches wrt: > >a) general increase of complexity > >b) the fact that they only partially address the problem: anonymous page > faults are addressed, but lots of other places aren't. > >c) the fact that they address one particular part of one particular > workload on exceedingly rare machines. > >I believe that Nick has plans to address b). > >I'd like us to thrash this out (again), please. Hugh, could you (for the >nth and final time) describe your concerns with these patches? > > That's true I do have a more general API that gives a bit more flexibility in the arch implementation, and allows complete removal of ptl... I'd like to get time to finish that up and get it working on ppc64 and see it in the kernel, however it is very intrusive (eg. does things like remove ptl from around mmu gather operations). Basically it is going to take a long time to get everyone on side even if the patch was 100% ready today (which it isn't). If the big ticket item is taking the ptl out of the anonymous fault path, then we probably should forget my stuff and consider Christoph's on its own merits. FWIW, I don't think it is an unreasonable approach to solving the problem at hand in a fairly unintrusive manner. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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